aarch64-none-linux-gnu-12.2.1/aarch64-none-linux-gnu/libc/usr/share/info/libc.info-15

This is libc.info, produced by makeinfo version 5.1 from libc.texinfo.

This is ‘The GNU C Library Reference Manual’, for version 2.36 (Arm).

   Copyright © 1993–2022 Free Software Foundation, Inc.

   Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with the
Invariant Sections being “Free Software Needs Free Documentation” and
“GNU Lesser General Public License”, the Front-Cover texts being “A GNU
Manual”, and with the Back-Cover Texts as in (a) below.  A copy of the
license is included in the section entitled "GNU Free Documentation
License".

   (a) The FSF’s Back-Cover Text is: “You have the freedom to copy and
modify this GNU manual.  Buying copies from the FSF supports it in
developing GNU and promoting software freedom.”
INFO-DIR-SECTION Software libraries
START-INFO-DIR-ENTRY
* Libc: (libc).                 C library.
END-INFO-DIR-ENTRY

INFO-DIR-SECTION GNU C library functions and macros
START-INFO-DIR-ENTRY
* ALTWERASE: (libc)Local Modes.
* ARGP_ERR_UNKNOWN: (libc)Argp Parser Functions.
* ARG_MAX: (libc)General Limits.
* BC_BASE_MAX: (libc)Utility Limits.
* BC_DIM_MAX: (libc)Utility Limits.
* BC_SCALE_MAX: (libc)Utility Limits.
* BC_STRING_MAX: (libc)Utility Limits.
* BRKINT: (libc)Input Modes.
* BUFSIZ: (libc)Controlling Buffering.
* CCTS_OFLOW: (libc)Control Modes.
* CHAR_BIT: (libc)Width of Type.
* CHILD_MAX: (libc)General Limits.
* CIGNORE: (libc)Control Modes.
* CLK_TCK: (libc)Processor Time.
* CLOCAL: (libc)Control Modes.
* CLOCKS_PER_SEC: (libc)CPU Time.
* CLOCK_MONOTONIC: (libc)Getting the Time.
* CLOCK_REALTIME: (libc)Getting the Time.
* COLL_WEIGHTS_MAX: (libc)Utility Limits.
* CPU_CLR: (libc)CPU Affinity.
* CPU_FEATURE_ACTIVE: (libc)X86.
* CPU_FEATURE_PRESENT: (libc)X86.
* CPU_ISSET: (libc)CPU Affinity.
* CPU_SET: (libc)CPU Affinity.
* CPU_SETSIZE: (libc)CPU Affinity.
* CPU_ZERO: (libc)CPU Affinity.
* CREAD: (libc)Control Modes.
* CRTS_IFLOW: (libc)Control Modes.
* CS5: (libc)Control Modes.
* CS6: (libc)Control Modes.
* CS7: (libc)Control Modes.
* CS8: (libc)Control Modes.
* CSIZE: (libc)Control Modes.
* CSTOPB: (libc)Control Modes.
* DLFO_EH_SEGMENT_TYPE: (libc)Dynamic Linker Introspection.
* DLFO_STRUCT_HAS_EH_COUNT: (libc)Dynamic Linker Introspection.
* DLFO_STRUCT_HAS_EH_DBASE: (libc)Dynamic Linker Introspection.
* DTTOIF: (libc)Directory Entries.
* E2BIG: (libc)Error Codes.
* EACCES: (libc)Error Codes.
* EADDRINUSE: (libc)Error Codes.
* EADDRNOTAVAIL: (libc)Error Codes.
* EADV: (libc)Error Codes.
* EAFNOSUPPORT: (libc)Error Codes.
* EAGAIN: (libc)Error Codes.
* EALREADY: (libc)Error Codes.
* EAUTH: (libc)Error Codes.
* EBACKGROUND: (libc)Error Codes.
* EBADE: (libc)Error Codes.
* EBADF: (libc)Error Codes.
* EBADFD: (libc)Error Codes.
* EBADMSG: (libc)Error Codes.
* EBADR: (libc)Error Codes.
* EBADRPC: (libc)Error Codes.
* EBADRQC: (libc)Error Codes.
* EBADSLT: (libc)Error Codes.
* EBFONT: (libc)Error Codes.
* EBUSY: (libc)Error Codes.
* ECANCELED: (libc)Error Codes.
* ECHILD: (libc)Error Codes.
* ECHO: (libc)Local Modes.
* ECHOCTL: (libc)Local Modes.
* ECHOE: (libc)Local Modes.
* ECHOK: (libc)Local Modes.
* ECHOKE: (libc)Local Modes.
* ECHONL: (libc)Local Modes.
* ECHOPRT: (libc)Local Modes.
* ECHRNG: (libc)Error Codes.
* ECOMM: (libc)Error Codes.
* ECONNABORTED: (libc)Error Codes.
* ECONNREFUSED: (libc)Error Codes.
* ECONNRESET: (libc)Error Codes.
* ED: (libc)Error Codes.
* EDEADLK: (libc)Error Codes.
* EDEADLOCK: (libc)Error Codes.
* EDESTADDRREQ: (libc)Error Codes.
* EDIED: (libc)Error Codes.
* EDOM: (libc)Error Codes.
* EDOTDOT: (libc)Error Codes.
* EDQUOT: (libc)Error Codes.
* EEXIST: (libc)Error Codes.
* EFAULT: (libc)Error Codes.
* EFBIG: (libc)Error Codes.
* EFTYPE: (libc)Error Codes.
* EGRATUITOUS: (libc)Error Codes.
* EGREGIOUS: (libc)Error Codes.
* EHOSTDOWN: (libc)Error Codes.
* EHOSTUNREACH: (libc)Error Codes.
* EHWPOISON: (libc)Error Codes.
* EIDRM: (libc)Error Codes.
* EIEIO: (libc)Error Codes.
* EILSEQ: (libc)Error Codes.
* EINPROGRESS: (libc)Error Codes.
* EINTR: (libc)Error Codes.
* EINVAL: (libc)Error Codes.
* EIO: (libc)Error Codes.
* EISCONN: (libc)Error Codes.
* EISDIR: (libc)Error Codes.
* EISNAM: (libc)Error Codes.
* EKEYEXPIRED: (libc)Error Codes.
* EKEYREJECTED: (libc)Error Codes.
* EKEYREVOKED: (libc)Error Codes.
* EL2HLT: (libc)Error Codes.
* EL2NSYNC: (libc)Error Codes.
* EL3HLT: (libc)Error Codes.
* EL3RST: (libc)Error Codes.
* ELIBACC: (libc)Error Codes.
* ELIBBAD: (libc)Error Codes.
* ELIBEXEC: (libc)Error Codes.
* ELIBMAX: (libc)Error Codes.
* ELIBSCN: (libc)Error Codes.
* ELNRNG: (libc)Error Codes.
* ELOOP: (libc)Error Codes.
* EMEDIUMTYPE: (libc)Error Codes.
* EMFILE: (libc)Error Codes.
* EMLINK: (libc)Error Codes.
* EMSGSIZE: (libc)Error Codes.
* EMULTIHOP: (libc)Error Codes.
* ENAMETOOLONG: (libc)Error Codes.
* ENAVAIL: (libc)Error Codes.
* ENEEDAUTH: (libc)Error Codes.
* ENETDOWN: (libc)Error Codes.
* ENETRESET: (libc)Error Codes.
* ENETUNREACH: (libc)Error Codes.
* ENFILE: (libc)Error Codes.
* ENOANO: (libc)Error Codes.
* ENOBUFS: (libc)Error Codes.
* ENOCSI: (libc)Error Codes.
* ENODATA: (libc)Error Codes.
* ENODEV: (libc)Error Codes.
* ENOENT: (libc)Error Codes.
* ENOEXEC: (libc)Error Codes.
* ENOKEY: (libc)Error Codes.
* ENOLCK: (libc)Error Codes.
* ENOLINK: (libc)Error Codes.
* ENOMEDIUM: (libc)Error Codes.
* ENOMEM: (libc)Error Codes.
* ENOMSG: (libc)Error Codes.
* ENONET: (libc)Error Codes.
* ENOPKG: (libc)Error Codes.
* ENOPROTOOPT: (libc)Error Codes.
* ENOSPC: (libc)Error Codes.
* ENOSR: (libc)Error Codes.
* ENOSTR: (libc)Error Codes.
* ENOSYS: (libc)Error Codes.
* ENOTBLK: (libc)Error Codes.
* ENOTCONN: (libc)Error Codes.
* ENOTDIR: (libc)Error Codes.
* ENOTEMPTY: (libc)Error Codes.
* ENOTNAM: (libc)Error Codes.
* ENOTRECOVERABLE: (libc)Error Codes.
* ENOTSOCK: (libc)Error Codes.
* ENOTSUP: (libc)Error Codes.
* ENOTTY: (libc)Error Codes.
* ENOTUNIQ: (libc)Error Codes.
* ENXIO: (libc)Error Codes.
* EOF: (libc)EOF and Errors.
* EOPNOTSUPP: (libc)Error Codes.
* EOVERFLOW: (libc)Error Codes.
* EOWNERDEAD: (libc)Error Codes.
* EPERM: (libc)Error Codes.
* EPFNOSUPPORT: (libc)Error Codes.
* EPIPE: (libc)Error Codes.
* EPROCLIM: (libc)Error Codes.
* EPROCUNAVAIL: (libc)Error Codes.
* EPROGMISMATCH: (libc)Error Codes.
* EPROGUNAVAIL: (libc)Error Codes.
* EPROTO: (libc)Error Codes.
* EPROTONOSUPPORT: (libc)Error Codes.
* EPROTOTYPE: (libc)Error Codes.
* EQUIV_CLASS_MAX: (libc)Utility Limits.
* ERANGE: (libc)Error Codes.
* EREMCHG: (libc)Error Codes.
* EREMOTE: (libc)Error Codes.
* EREMOTEIO: (libc)Error Codes.
* ERESTART: (libc)Error Codes.
* ERFKILL: (libc)Error Codes.
* EROFS: (libc)Error Codes.
* ERPCMISMATCH: (libc)Error Codes.
* ESHUTDOWN: (libc)Error Codes.
* ESOCKTNOSUPPORT: (libc)Error Codes.
* ESPIPE: (libc)Error Codes.
* ESRCH: (libc)Error Codes.
* ESRMNT: (libc)Error Codes.
* ESTALE: (libc)Error Codes.
* ESTRPIPE: (libc)Error Codes.
* ETIME: (libc)Error Codes.
* ETIMEDOUT: (libc)Error Codes.
* ETOOMANYREFS: (libc)Error Codes.
* ETXTBSY: (libc)Error Codes.
* EUCLEAN: (libc)Error Codes.
* EUNATCH: (libc)Error Codes.
* EUSERS: (libc)Error Codes.
* EWOULDBLOCK: (libc)Error Codes.
* EXDEV: (libc)Error Codes.
* EXFULL: (libc)Error Codes.
* EXIT_FAILURE: (libc)Exit Status.
* EXIT_SUCCESS: (libc)Exit Status.
* EXPR_NEST_MAX: (libc)Utility Limits.
* FD_CLOEXEC: (libc)Descriptor Flags.
* FD_CLR: (libc)Waiting for I/O.
* FD_ISSET: (libc)Waiting for I/O.
* FD_SET: (libc)Waiting for I/O.
* FD_SETSIZE: (libc)Waiting for I/O.
* FD_ZERO: (libc)Waiting for I/O.
* FE_SNANS_ALWAYS_SIGNAL: (libc)Infinity and NaN.
* FILENAME_MAX: (libc)Limits for Files.
* FLUSHO: (libc)Local Modes.
* FOPEN_MAX: (libc)Opening Streams.
* FP_ILOGB0: (libc)Exponents and Logarithms.
* FP_ILOGBNAN: (libc)Exponents and Logarithms.
* FP_LLOGB0: (libc)Exponents and Logarithms.
* FP_LLOGBNAN: (libc)Exponents and Logarithms.
* F_DUPFD: (libc)Duplicating Descriptors.
* F_GETFD: (libc)Descriptor Flags.
* F_GETFL: (libc)Getting File Status Flags.
* F_GETLK: (libc)File Locks.
* F_GETOWN: (libc)Interrupt Input.
* F_OFD_GETLK: (libc)Open File Description Locks.
* F_OFD_SETLK: (libc)Open File Description Locks.
* F_OFD_SETLKW: (libc)Open File Description Locks.
* F_OK: (libc)Testing File Access.
* F_SETFD: (libc)Descriptor Flags.
* F_SETFL: (libc)Getting File Status Flags.
* F_SETLK: (libc)File Locks.
* F_SETLKW: (libc)File Locks.
* F_SETOWN: (libc)Interrupt Input.
* HUGE_VAL: (libc)Math Error Reporting.
* HUGE_VALF: (libc)Math Error Reporting.
* HUGE_VALL: (libc)Math Error Reporting.
* HUGE_VAL_FN: (libc)Math Error Reporting.
* HUGE_VAL_FNx: (libc)Math Error Reporting.
* HUPCL: (libc)Control Modes.
* I: (libc)Complex Numbers.
* ICANON: (libc)Local Modes.
* ICRNL: (libc)Input Modes.
* IEXTEN: (libc)Local Modes.
* IFNAMSIZ: (libc)Interface Naming.
* IFTODT: (libc)Directory Entries.
* IGNBRK: (libc)Input Modes.
* IGNCR: (libc)Input Modes.
* IGNPAR: (libc)Input Modes.
* IMAXBEL: (libc)Input Modes.
* INADDR_ANY: (libc)Host Address Data Type.
* INADDR_BROADCAST: (libc)Host Address Data Type.
* INADDR_LOOPBACK: (libc)Host Address Data Type.
* INADDR_NONE: (libc)Host Address Data Type.
* INFINITY: (libc)Infinity and NaN.
* INLCR: (libc)Input Modes.
* INPCK: (libc)Input Modes.
* IPPORT_RESERVED: (libc)Ports.
* IPPORT_USERRESERVED: (libc)Ports.
* ISIG: (libc)Local Modes.
* ISTRIP: (libc)Input Modes.
* IXANY: (libc)Input Modes.
* IXOFF: (libc)Input Modes.
* IXON: (libc)Input Modes.
* LINE_MAX: (libc)Utility Limits.
* LINK_MAX: (libc)Limits for Files.
* L_ctermid: (libc)Identifying the Terminal.
* L_cuserid: (libc)Who Logged In.
* L_tmpnam: (libc)Temporary Files.
* MAXNAMLEN: (libc)Limits for Files.
* MAXSYMLINKS: (libc)Symbolic Links.
* MAX_CANON: (libc)Limits for Files.
* MAX_INPUT: (libc)Limits for Files.
* MB_CUR_MAX: (libc)Selecting the Conversion.
* MB_LEN_MAX: (libc)Selecting the Conversion.
* MDMBUF: (libc)Control Modes.
* MSG_DONTROUTE: (libc)Socket Data Options.
* MSG_OOB: (libc)Socket Data Options.
* MSG_PEEK: (libc)Socket Data Options.
* NAME_MAX: (libc)Limits for Files.
* NAN: (libc)Infinity and NaN.
* NCCS: (libc)Mode Data Types.
* NGROUPS_MAX: (libc)General Limits.
* NOFLSH: (libc)Local Modes.
* NOKERNINFO: (libc)Local Modes.
* NSIG: (libc)Standard Signals.
* NULL: (libc)Null Pointer Constant.
* ONLCR: (libc)Output Modes.
* ONOEOT: (libc)Output Modes.
* OPEN_MAX: (libc)General Limits.
* OPOST: (libc)Output Modes.
* OXTABS: (libc)Output Modes.
* O_ACCMODE: (libc)Access Modes.
* O_APPEND: (libc)Operating Modes.
* O_ASYNC: (libc)Operating Modes.
* O_CREAT: (libc)Open-time Flags.
* O_DIRECTORY: (libc)Open-time Flags.
* O_EXCL: (libc)Open-time Flags.
* O_EXEC: (libc)Access Modes.
* O_EXLOCK: (libc)Open-time Flags.
* O_FSYNC: (libc)Operating Modes.
* O_IGNORE_CTTY: (libc)Open-time Flags.
* O_NDELAY: (libc)Operating Modes.
* O_NOATIME: (libc)Operating Modes.
* O_NOCTTY: (libc)Open-time Flags.
* O_NOFOLLOW: (libc)Open-time Flags.
* O_NOLINK: (libc)Open-time Flags.
* O_NONBLOCK: (libc)Open-time Flags.
* O_NONBLOCK: (libc)Operating Modes.
* O_NOTRANS: (libc)Open-time Flags.
* O_PATH: (libc)Access Modes.
* O_RDONLY: (libc)Access Modes.
* O_RDWR: (libc)Access Modes.
* O_READ: (libc)Access Modes.
* O_SHLOCK: (libc)Open-time Flags.
* O_SYNC: (libc)Operating Modes.
* O_TMPFILE: (libc)Open-time Flags.
* O_TRUNC: (libc)Open-time Flags.
* O_WRITE: (libc)Access Modes.
* O_WRONLY: (libc)Access Modes.
* PARENB: (libc)Control Modes.
* PARMRK: (libc)Input Modes.
* PARODD: (libc)Control Modes.
* PATH_MAX: (libc)Limits for Files.
* PA_FLAG_MASK: (libc)Parsing a Template String.
* PENDIN: (libc)Local Modes.
* PF_FILE: (libc)Local Namespace Details.
* PF_INET6: (libc)Internet Namespace.
* PF_INET: (libc)Internet Namespace.
* PF_LOCAL: (libc)Local Namespace Details.
* PF_UNIX: (libc)Local Namespace Details.
* PIPE_BUF: (libc)Limits for Files.
* PTHREAD_ATTR_NO_SIGMASK_NP: (libc)Initial Thread Signal Mask.
* P_tmpdir: (libc)Temporary Files.
* RAND_MAX: (libc)ISO Random.
* RE_DUP_MAX: (libc)General Limits.
* RLIM_INFINITY: (libc)Limits on Resources.
* RSEQ_SIG: (libc)Restartable Sequences.
* R_OK: (libc)Testing File Access.
* SA_NOCLDSTOP: (libc)Flags for Sigaction.
* SA_ONSTACK: (libc)Flags for Sigaction.
* SA_RESTART: (libc)Flags for Sigaction.
* SEEK_CUR: (libc)File Positioning.
* SEEK_END: (libc)File Positioning.
* SEEK_SET: (libc)File Positioning.
* SIGABRT: (libc)Program Error Signals.
* SIGALRM: (libc)Alarm Signals.
* SIGBUS: (libc)Program Error Signals.
* SIGCHLD: (libc)Job Control Signals.
* SIGCLD: (libc)Job Control Signals.
* SIGCONT: (libc)Job Control Signals.
* SIGEMT: (libc)Program Error Signals.
* SIGFPE: (libc)Program Error Signals.
* SIGHUP: (libc)Termination Signals.
* SIGILL: (libc)Program Error Signals.
* SIGINFO: (libc)Miscellaneous Signals.
* SIGINT: (libc)Termination Signals.
* SIGIO: (libc)Asynchronous I/O Signals.
* SIGIOT: (libc)Program Error Signals.
* SIGKILL: (libc)Termination Signals.
* SIGLOST: (libc)Operation Error Signals.
* SIGPIPE: (libc)Operation Error Signals.
* SIGPOLL: (libc)Asynchronous I/O Signals.
* SIGPROF: (libc)Alarm Signals.
* SIGQUIT: (libc)Termination Signals.
* SIGSEGV: (libc)Program Error Signals.
* SIGSTOP: (libc)Job Control Signals.
* SIGSYS: (libc)Program Error Signals.
* SIGTERM: (libc)Termination Signals.
* SIGTRAP: (libc)Program Error Signals.
* SIGTSTP: (libc)Job Control Signals.
* SIGTTIN: (libc)Job Control Signals.
* SIGTTOU: (libc)Job Control Signals.
* SIGURG: (libc)Asynchronous I/O Signals.
* SIGUSR1: (libc)Miscellaneous Signals.
* SIGUSR2: (libc)Miscellaneous Signals.
* SIGVTALRM: (libc)Alarm Signals.
* SIGWINCH: (libc)Miscellaneous Signals.
* SIGXCPU: (libc)Operation Error Signals.
* SIGXFSZ: (libc)Operation Error Signals.
* SIG_ERR: (libc)Basic Signal Handling.
* SNAN: (libc)Infinity and NaN.
* SNANF: (libc)Infinity and NaN.
* SNANFN: (libc)Infinity and NaN.
* SNANFNx: (libc)Infinity and NaN.
* SNANL: (libc)Infinity and NaN.
* SOCK_DGRAM: (libc)Communication Styles.
* SOCK_RAW: (libc)Communication Styles.
* SOCK_RDM: (libc)Communication Styles.
* SOCK_SEQPACKET: (libc)Communication Styles.
* SOCK_STREAM: (libc)Communication Styles.
* SOL_SOCKET: (libc)Socket-Level Options.
* SSIZE_MAX: (libc)General Limits.
* STREAM_MAX: (libc)General Limits.
* SUN_LEN: (libc)Local Namespace Details.
* S_IFMT: (libc)Testing File Type.
* S_ISBLK: (libc)Testing File Type.
* S_ISCHR: (libc)Testing File Type.
* S_ISDIR: (libc)Testing File Type.
* S_ISFIFO: (libc)Testing File Type.
* S_ISLNK: (libc)Testing File Type.
* S_ISREG: (libc)Testing File Type.
* S_ISSOCK: (libc)Testing File Type.
* S_TYPEISMQ: (libc)Testing File Type.
* S_TYPEISSEM: (libc)Testing File Type.
* S_TYPEISSHM: (libc)Testing File Type.
* TMP_MAX: (libc)Temporary Files.
* TOSTOP: (libc)Local Modes.
* TZNAME_MAX: (libc)General Limits.
* VDISCARD: (libc)Other Special.
* VDSUSP: (libc)Signal Characters.
* VEOF: (libc)Editing Characters.
* VEOL2: (libc)Editing Characters.
* VEOL: (libc)Editing Characters.
* VERASE: (libc)Editing Characters.
* VINTR: (libc)Signal Characters.
* VKILL: (libc)Editing Characters.
* VLNEXT: (libc)Other Special.
* VMIN: (libc)Noncanonical Input.
* VQUIT: (libc)Signal Characters.
* VREPRINT: (libc)Editing Characters.
* VSTART: (libc)Start/Stop Characters.
* VSTATUS: (libc)Other Special.
* VSTOP: (libc)Start/Stop Characters.
* VSUSP: (libc)Signal Characters.
* VTIME: (libc)Noncanonical Input.
* VWERASE: (libc)Editing Characters.
* WCHAR_MAX: (libc)Extended Char Intro.
* WCHAR_MIN: (libc)Extended Char Intro.
* WCOREDUMP: (libc)Process Completion Status.
* WEOF: (libc)EOF and Errors.
* WEOF: (libc)Extended Char Intro.
* WEXITSTATUS: (libc)Process Completion Status.
* WIFEXITED: (libc)Process Completion Status.
* WIFSIGNALED: (libc)Process Completion Status.
* WIFSTOPPED: (libc)Process Completion Status.
* WSTOPSIG: (libc)Process Completion Status.
* WTERMSIG: (libc)Process Completion Status.
* W_OK: (libc)Testing File Access.
* X_OK: (libc)Testing File Access.
* _Complex_I: (libc)Complex Numbers.
* _Exit: (libc)Termination Internals.
* _Fork: (libc)Creating a Process.
* _IOFBF: (libc)Controlling Buffering.
* _IOLBF: (libc)Controlling Buffering.
* _IONBF: (libc)Controlling Buffering.
* _Imaginary_I: (libc)Complex Numbers.
* _PATH_UTMP: (libc)Manipulating the Database.
* _PATH_WTMP: (libc)Manipulating the Database.
* _POSIX2_C_DEV: (libc)System Options.
* _POSIX2_C_VERSION: (libc)Version Supported.
* _POSIX2_FORT_DEV: (libc)System Options.
* _POSIX2_FORT_RUN: (libc)System Options.
* _POSIX2_LOCALEDEF: (libc)System Options.
* _POSIX2_SW_DEV: (libc)System Options.
* _POSIX_CHOWN_RESTRICTED: (libc)Options for Files.
* _POSIX_JOB_CONTROL: (libc)System Options.
* _POSIX_NO_TRUNC: (libc)Options for Files.
* _POSIX_SAVED_IDS: (libc)System Options.
* _POSIX_VDISABLE: (libc)Options for Files.
* _POSIX_VERSION: (libc)Version Supported.
* __fbufsize: (libc)Controlling Buffering.
* __flbf: (libc)Controlling Buffering.
* __fpending: (libc)Controlling Buffering.
* __fpurge: (libc)Flushing Buffers.
* __freadable: (libc)Opening Streams.
* __freading: (libc)Opening Streams.
* __fsetlocking: (libc)Streams and Threads.
* __fwritable: (libc)Opening Streams.
* __fwriting: (libc)Opening Streams.
* __gconv_end_fct: (libc)glibc iconv Implementation.
* __gconv_fct: (libc)glibc iconv Implementation.
* __gconv_init_fct: (libc)glibc iconv Implementation.
* __ppc_get_timebase: (libc)PowerPC.
* __ppc_get_timebase_freq: (libc)PowerPC.
* __ppc_mdoio: (libc)PowerPC.
* __ppc_mdoom: (libc)PowerPC.
* __ppc_set_ppr_low: (libc)PowerPC.
* __ppc_set_ppr_med: (libc)PowerPC.
* __ppc_set_ppr_med_high: (libc)PowerPC.
* __ppc_set_ppr_med_low: (libc)PowerPC.
* __ppc_set_ppr_very_low: (libc)PowerPC.
* __ppc_yield: (libc)PowerPC.
* __riscv_flush_icache: (libc)RISC-V.
* __va_copy: (libc)Argument Macros.
* __x86_get_cpuid_feature_leaf: (libc)X86.
* _dl_find_object: (libc)Dynamic Linker Introspection.
* _exit: (libc)Termination Internals.
* _flushlbf: (libc)Flushing Buffers.
* _tolower: (libc)Case Conversion.
* _toupper: (libc)Case Conversion.
* a64l: (libc)Encode Binary Data.
* abort: (libc)Aborting a Program.
* abs: (libc)Absolute Value.
* accept: (libc)Accepting Connections.
* access: (libc)Testing File Access.
* acos: (libc)Inverse Trig Functions.
* acosf: (libc)Inverse Trig Functions.
* acosfN: (libc)Inverse Trig Functions.
* acosfNx: (libc)Inverse Trig Functions.
* acosh: (libc)Hyperbolic Functions.
* acoshf: (libc)Hyperbolic Functions.
* acoshfN: (libc)Hyperbolic Functions.
* acoshfNx: (libc)Hyperbolic Functions.
* acoshl: (libc)Hyperbolic Functions.
* acosl: (libc)Inverse Trig Functions.
* addmntent: (libc)mtab.
* addseverity: (libc)Adding Severity Classes.
* adjtime: (libc)Setting and Adjusting the Time.
* adjtimex: (libc)Setting and Adjusting the Time.
* aio_cancel64: (libc)Cancel AIO Operations.
* aio_cancel: (libc)Cancel AIO Operations.
* aio_error64: (libc)Status of AIO Operations.
* aio_error: (libc)Status of AIO Operations.
* aio_fsync64: (libc)Synchronizing AIO Operations.
* aio_fsync: (libc)Synchronizing AIO Operations.
* aio_init: (libc)Configuration of AIO.
* aio_read64: (libc)Asynchronous Reads/Writes.
* aio_read: (libc)Asynchronous Reads/Writes.
* aio_return64: (libc)Status of AIO Operations.
* aio_return: (libc)Status of AIO Operations.
* aio_suspend64: (libc)Synchronizing AIO Operations.
* aio_suspend: (libc)Synchronizing AIO Operations.
* aio_write64: (libc)Asynchronous Reads/Writes.
* aio_write: (libc)Asynchronous Reads/Writes.
* alarm: (libc)Setting an Alarm.
* aligned_alloc: (libc)Aligned Memory Blocks.
* alloca: (libc)Variable Size Automatic.
* alphasort64: (libc)Scanning Directory Content.
* alphasort: (libc)Scanning Directory Content.
* arc4random: (libc)High Quality Random.
* arc4random_buf: (libc)High Quality Random.
* arc4random_uniform: (libc)High Quality Random.
* argp_error: (libc)Argp Helper Functions.
* argp_failure: (libc)Argp Helper Functions.
* argp_help: (libc)Argp Help.
* argp_parse: (libc)Argp.
* argp_state_help: (libc)Argp Helper Functions.
* argp_usage: (libc)Argp Helper Functions.
* argz_add: (libc)Argz Functions.
* argz_add_sep: (libc)Argz Functions.
* argz_append: (libc)Argz Functions.
* argz_count: (libc)Argz Functions.
* argz_create: (libc)Argz Functions.
* argz_create_sep: (libc)Argz Functions.
* argz_delete: (libc)Argz Functions.
* argz_extract: (libc)Argz Functions.
* argz_insert: (libc)Argz Functions.
* argz_next: (libc)Argz Functions.
* argz_replace: (libc)Argz Functions.
* argz_stringify: (libc)Argz Functions.
* asctime: (libc)Formatting Calendar Time.
* asctime_r: (libc)Formatting Calendar Time.
* asin: (libc)Inverse Trig Functions.
* asinf: (libc)Inverse Trig Functions.
* asinfN: (libc)Inverse Trig Functions.
* asinfNx: (libc)Inverse Trig Functions.
* asinh: (libc)Hyperbolic Functions.
* asinhf: (libc)Hyperbolic Functions.
* asinhfN: (libc)Hyperbolic Functions.
* asinhfNx: (libc)Hyperbolic Functions.
* asinhl: (libc)Hyperbolic Functions.
* asinl: (libc)Inverse Trig Functions.
* asprintf: (libc)Dynamic Output.
* assert: (libc)Consistency Checking.
* assert_perror: (libc)Consistency Checking.
* atan2: (libc)Inverse Trig Functions.
* atan2f: (libc)Inverse Trig Functions.
* atan2fN: (libc)Inverse Trig Functions.
* atan2fNx: (libc)Inverse Trig Functions.
* atan2l: (libc)Inverse Trig Functions.
* atan: (libc)Inverse Trig Functions.
* atanf: (libc)Inverse Trig Functions.
* atanfN: (libc)Inverse Trig Functions.
* atanfNx: (libc)Inverse Trig Functions.
* atanh: (libc)Hyperbolic Functions.
* atanhf: (libc)Hyperbolic Functions.
* atanhfN: (libc)Hyperbolic Functions.
* atanhfNx: (libc)Hyperbolic Functions.
* atanhl: (libc)Hyperbolic Functions.
* atanl: (libc)Inverse Trig Functions.
* atexit: (libc)Cleanups on Exit.
* atof: (libc)Parsing of Floats.
* atoi: (libc)Parsing of Integers.
* atol: (libc)Parsing of Integers.
* atoll: (libc)Parsing of Integers.
* backtrace: (libc)Backtraces.
* backtrace_symbols: (libc)Backtraces.
* backtrace_symbols_fd: (libc)Backtraces.
* basename: (libc)Finding Tokens in a String.
* basename: (libc)Finding Tokens in a String.
* bcmp: (libc)String/Array Comparison.
* bcopy: (libc)Copying Strings and Arrays.
* bind: (libc)Setting Address.
* bind_textdomain_codeset: (libc)Charset conversion in gettext.
* bindtextdomain: (libc)Locating gettext catalog.
* brk: (libc)Resizing the Data Segment.
* bsearch: (libc)Array Search Function.
* btowc: (libc)Converting a Character.
* bzero: (libc)Copying Strings and Arrays.
* cabs: (libc)Absolute Value.
* cabsf: (libc)Absolute Value.
* cabsfN: (libc)Absolute Value.
* cabsfNx: (libc)Absolute Value.
* cabsl: (libc)Absolute Value.
* cacos: (libc)Inverse Trig Functions.
* cacosf: (libc)Inverse Trig Functions.
* cacosfN: (libc)Inverse Trig Functions.
* cacosfNx: (libc)Inverse Trig Functions.
* cacosh: (libc)Hyperbolic Functions.
* cacoshf: (libc)Hyperbolic Functions.
* cacoshfN: (libc)Hyperbolic Functions.
* cacoshfNx: (libc)Hyperbolic Functions.
* cacoshl: (libc)Hyperbolic Functions.
* cacosl: (libc)Inverse Trig Functions.
* call_once: (libc)Call Once.
* calloc: (libc)Allocating Cleared Space.
* canonicalize: (libc)FP Bit Twiddling.
* canonicalize_file_name: (libc)Symbolic Links.
* canonicalizef: (libc)FP Bit Twiddling.
* canonicalizefN: (libc)FP Bit Twiddling.
* canonicalizefNx: (libc)FP Bit Twiddling.
* canonicalizel: (libc)FP Bit Twiddling.
* carg: (libc)Operations on Complex.
* cargf: (libc)Operations on Complex.
* cargfN: (libc)Operations on Complex.
* cargfNx: (libc)Operations on Complex.
* cargl: (libc)Operations on Complex.
* casin: (libc)Inverse Trig Functions.
* casinf: (libc)Inverse Trig Functions.
* casinfN: (libc)Inverse Trig Functions.
* casinfNx: (libc)Inverse Trig Functions.
* casinh: (libc)Hyperbolic Functions.
* casinhf: (libc)Hyperbolic Functions.
* casinhfN: (libc)Hyperbolic Functions.
* casinhfNx: (libc)Hyperbolic Functions.
* casinhl: (libc)Hyperbolic Functions.
* casinl: (libc)Inverse Trig Functions.
* catan: (libc)Inverse Trig Functions.
* catanf: (libc)Inverse Trig Functions.
* catanfN: (libc)Inverse Trig Functions.
* catanfNx: (libc)Inverse Trig Functions.
* catanh: (libc)Hyperbolic Functions.
* catanhf: (libc)Hyperbolic Functions.
* catanhfN: (libc)Hyperbolic Functions.
* catanhfNx: (libc)Hyperbolic Functions.
* catanhl: (libc)Hyperbolic Functions.
* catanl: (libc)Inverse Trig Functions.
* catclose: (libc)The catgets Functions.
* catgets: (libc)The catgets Functions.
* catopen: (libc)The catgets Functions.
* cbrt: (libc)Exponents and Logarithms.
* cbrtf: (libc)Exponents and Logarithms.
* cbrtfN: (libc)Exponents and Logarithms.
* cbrtfNx: (libc)Exponents and Logarithms.
* cbrtl: (libc)Exponents and Logarithms.
* ccos: (libc)Trig Functions.
* ccosf: (libc)Trig Functions.
* ccosfN: (libc)Trig Functions.
* ccosfNx: (libc)Trig Functions.
* ccosh: (libc)Hyperbolic Functions.
* ccoshf: (libc)Hyperbolic Functions.
* ccoshfN: (libc)Hyperbolic Functions.
* ccoshfNx: (libc)Hyperbolic Functions.
* ccoshl: (libc)Hyperbolic Functions.
* ccosl: (libc)Trig Functions.
* ceil: (libc)Rounding Functions.
* ceilf: (libc)Rounding Functions.
* ceilfN: (libc)Rounding Functions.
* ceilfNx: (libc)Rounding Functions.
* ceill: (libc)Rounding Functions.
* cexp: (libc)Exponents and Logarithms.
* cexpf: (libc)Exponents and Logarithms.
* cexpfN: (libc)Exponents and Logarithms.
* cexpfNx: (libc)Exponents and Logarithms.
* cexpl: (libc)Exponents and Logarithms.
* cfgetispeed: (libc)Line Speed.
* cfgetospeed: (libc)Line Speed.
* cfmakeraw: (libc)Noncanonical Input.
* cfsetispeed: (libc)Line Speed.
* cfsetospeed: (libc)Line Speed.
* cfsetspeed: (libc)Line Speed.
* chdir: (libc)Working Directory.
* chmod: (libc)Setting Permissions.
* chown: (libc)File Owner.
* cimag: (libc)Operations on Complex.
* cimagf: (libc)Operations on Complex.
* cimagfN: (libc)Operations on Complex.
* cimagfNx: (libc)Operations on Complex.
* cimagl: (libc)Operations on Complex.
* clearenv: (libc)Environment Access.
* clearerr: (libc)Error Recovery.
* clearerr_unlocked: (libc)Error Recovery.
* clock: (libc)CPU Time.
* clock_getres: (libc)Getting the Time.
* clock_gettime: (libc)Getting the Time.
* clock_settime: (libc)Setting and Adjusting the Time.
* clog10: (libc)Exponents and Logarithms.
* clog10f: (libc)Exponents and Logarithms.
* clog10fN: (libc)Exponents and Logarithms.
* clog10fNx: (libc)Exponents and Logarithms.
* clog10l: (libc)Exponents and Logarithms.
* clog: (libc)Exponents and Logarithms.
* clogf: (libc)Exponents and Logarithms.
* clogfN: (libc)Exponents and Logarithms.
* clogfNx: (libc)Exponents and Logarithms.
* clogl: (libc)Exponents and Logarithms.
* close: (libc)Opening and Closing Files.
* close_range: (libc)Opening and Closing Files.
* closedir: (libc)Reading/Closing Directory.
* closefrom: (libc)Opening and Closing Files.
* closelog: (libc)closelog.
* cnd_broadcast: (libc)ISO C Condition Variables.
* cnd_destroy: (libc)ISO C Condition Variables.
* cnd_init: (libc)ISO C Condition Variables.
* cnd_signal: (libc)ISO C Condition Variables.
* cnd_timedwait: (libc)ISO C Condition Variables.
* cnd_wait: (libc)ISO C Condition Variables.
* confstr: (libc)String Parameters.
* conj: (libc)Operations on Complex.
* conjf: (libc)Operations on Complex.
* conjfN: (libc)Operations on Complex.
* conjfNx: (libc)Operations on Complex.
* conjl: (libc)Operations on Complex.
* connect: (libc)Connecting.
* copy_file_range: (libc)Copying File Data.
* copysign: (libc)FP Bit Twiddling.
* copysignf: (libc)FP Bit Twiddling.
* copysignfN: (libc)FP Bit Twiddling.
* copysignfNx: (libc)FP Bit Twiddling.
* copysignl: (libc)FP Bit Twiddling.
* cos: (libc)Trig Functions.
* cosf: (libc)Trig Functions.
* cosfN: (libc)Trig Functions.
* cosfNx: (libc)Trig Functions.
* cosh: (libc)Hyperbolic Functions.
* coshf: (libc)Hyperbolic Functions.
* coshfN: (libc)Hyperbolic Functions.
* coshfNx: (libc)Hyperbolic Functions.
* coshl: (libc)Hyperbolic Functions.
* cosl: (libc)Trig Functions.
* cpow: (libc)Exponents and Logarithms.
* cpowf: (libc)Exponents and Logarithms.
* cpowfN: (libc)Exponents and Logarithms.
* cpowfNx: (libc)Exponents and Logarithms.
* cpowl: (libc)Exponents and Logarithms.
* cproj: (libc)Operations on Complex.
* cprojf: (libc)Operations on Complex.
* cprojfN: (libc)Operations on Complex.
* cprojfNx: (libc)Operations on Complex.
* cprojl: (libc)Operations on Complex.
* creal: (libc)Operations on Complex.
* crealf: (libc)Operations on Complex.
* crealfN: (libc)Operations on Complex.
* crealfNx: (libc)Operations on Complex.
* creall: (libc)Operations on Complex.
* creat64: (libc)Opening and Closing Files.
* creat: (libc)Opening and Closing Files.
* crypt: (libc)Passphrase Storage.
* crypt_r: (libc)Passphrase Storage.
* csin: (libc)Trig Functions.
* csinf: (libc)Trig Functions.
* csinfN: (libc)Trig Functions.
* csinfNx: (libc)Trig Functions.
* csinh: (libc)Hyperbolic Functions.
* csinhf: (libc)Hyperbolic Functions.
* csinhfN: (libc)Hyperbolic Functions.
* csinhfNx: (libc)Hyperbolic Functions.
* csinhl: (libc)Hyperbolic Functions.
* csinl: (libc)Trig Functions.
* csqrt: (libc)Exponents and Logarithms.
* csqrtf: (libc)Exponents and Logarithms.
* csqrtfN: (libc)Exponents and Logarithms.
* csqrtfNx: (libc)Exponents and Logarithms.
* csqrtl: (libc)Exponents and Logarithms.
* ctan: (libc)Trig Functions.
* ctanf: (libc)Trig Functions.
* ctanfN: (libc)Trig Functions.
* ctanfNx: (libc)Trig Functions.
* ctanh: (libc)Hyperbolic Functions.
* ctanhf: (libc)Hyperbolic Functions.
* ctanhfN: (libc)Hyperbolic Functions.
* ctanhfNx: (libc)Hyperbolic Functions.
* ctanhl: (libc)Hyperbolic Functions.
* ctanl: (libc)Trig Functions.
* ctermid: (libc)Identifying the Terminal.
* ctime: (libc)Formatting Calendar Time.
* ctime_r: (libc)Formatting Calendar Time.
* cuserid: (libc)Who Logged In.
* daddl: (libc)Misc FP Arithmetic.
* dcgettext: (libc)Translation with gettext.
* dcngettext: (libc)Advanced gettext functions.
* ddivl: (libc)Misc FP Arithmetic.
* dfmal: (libc)Misc FP Arithmetic.
* dgettext: (libc)Translation with gettext.
* difftime: (libc)Calculating Elapsed Time.
* dirfd: (libc)Opening a Directory.
* dirname: (libc)Finding Tokens in a String.
* div: (libc)Integer Division.
* dlinfo: (libc)Dynamic Linker Introspection.
* dmull: (libc)Misc FP Arithmetic.
* dngettext: (libc)Advanced gettext functions.
* drand48: (libc)SVID Random.
* drand48_r: (libc)SVID Random.
* drem: (libc)Remainder Functions.
* dremf: (libc)Remainder Functions.
* dreml: (libc)Remainder Functions.
* dsqrtl: (libc)Misc FP Arithmetic.
* dsubl: (libc)Misc FP Arithmetic.
* dup2: (libc)Duplicating Descriptors.
* dup: (libc)Duplicating Descriptors.
* ecvt: (libc)System V Number Conversion.
* ecvt_r: (libc)System V Number Conversion.
* endfsent: (libc)fstab.
* endgrent: (libc)Scanning All Groups.
* endhostent: (libc)Host Names.
* endmntent: (libc)mtab.
* endnetent: (libc)Networks Database.
* endnetgrent: (libc)Lookup Netgroup.
* endprotoent: (libc)Protocols Database.
* endpwent: (libc)Scanning All Users.
* endservent: (libc)Services Database.
* endutent: (libc)Manipulating the Database.
* endutxent: (libc)XPG Functions.
* envz_add: (libc)Envz Functions.
* envz_entry: (libc)Envz Functions.
* envz_get: (libc)Envz Functions.
* envz_merge: (libc)Envz Functions.
* envz_remove: (libc)Envz Functions.
* envz_strip: (libc)Envz Functions.
* erand48: (libc)SVID Random.
* erand48_r: (libc)SVID Random.
* erf: (libc)Special Functions.
* erfc: (libc)Special Functions.
* erfcf: (libc)Special Functions.
* erfcfN: (libc)Special Functions.
* erfcfNx: (libc)Special Functions.
* erfcl: (libc)Special Functions.
* erff: (libc)Special Functions.
* erffN: (libc)Special Functions.
* erffNx: (libc)Special Functions.
* erfl: (libc)Special Functions.
* err: (libc)Error Messages.
* errno: (libc)Checking for Errors.
* error: (libc)Error Messages.
* error_at_line: (libc)Error Messages.
* errx: (libc)Error Messages.
* execl: (libc)Executing a File.
* execle: (libc)Executing a File.
* execlp: (libc)Executing a File.
* execv: (libc)Executing a File.
* execve: (libc)Executing a File.
* execvp: (libc)Executing a File.
* exit: (libc)Normal Termination.
* exp10: (libc)Exponents and Logarithms.
* exp10f: (libc)Exponents and Logarithms.
* exp10fN: (libc)Exponents and Logarithms.
* exp10fNx: (libc)Exponents and Logarithms.
* exp10l: (libc)Exponents and Logarithms.
* exp2: (libc)Exponents and Logarithms.
* exp2f: (libc)Exponents and Logarithms.
* exp2fN: (libc)Exponents and Logarithms.
* exp2fNx: (libc)Exponents and Logarithms.
* exp2l: (libc)Exponents and Logarithms.
* exp: (libc)Exponents and Logarithms.
* expf: (libc)Exponents and Logarithms.
* expfN: (libc)Exponents and Logarithms.
* expfNx: (libc)Exponents and Logarithms.
* expl: (libc)Exponents and Logarithms.
* explicit_bzero: (libc)Erasing Sensitive Data.
* expm1: (libc)Exponents and Logarithms.
* expm1f: (libc)Exponents and Logarithms.
* expm1fN: (libc)Exponents and Logarithms.
* expm1fNx: (libc)Exponents and Logarithms.
* expm1l: (libc)Exponents and Logarithms.
* fMaddfN: (libc)Misc FP Arithmetic.
* fMaddfNx: (libc)Misc FP Arithmetic.
* fMdivfN: (libc)Misc FP Arithmetic.
* fMdivfNx: (libc)Misc FP Arithmetic.
* fMfmafN: (libc)Misc FP Arithmetic.
* fMfmafNx: (libc)Misc FP Arithmetic.
* fMmulfN: (libc)Misc FP Arithmetic.
* fMmulfNx: (libc)Misc FP Arithmetic.
* fMsqrtfN: (libc)Misc FP Arithmetic.
* fMsqrtfNx: (libc)Misc FP Arithmetic.
* fMsubfN: (libc)Misc FP Arithmetic.
* fMsubfNx: (libc)Misc FP Arithmetic.
* fMxaddfN: (libc)Misc FP Arithmetic.
* fMxaddfNx: (libc)Misc FP Arithmetic.
* fMxdivfN: (libc)Misc FP Arithmetic.
* fMxdivfNx: (libc)Misc FP Arithmetic.
* fMxfmafN: (libc)Misc FP Arithmetic.
* fMxfmafNx: (libc)Misc FP Arithmetic.
* fMxmulfN: (libc)Misc FP Arithmetic.
* fMxmulfNx: (libc)Misc FP Arithmetic.
* fMxsqrtfN: (libc)Misc FP Arithmetic.
* fMxsqrtfNx: (libc)Misc FP Arithmetic.
* fMxsubfN: (libc)Misc FP Arithmetic.
* fMxsubfNx: (libc)Misc FP Arithmetic.
* fabs: (libc)Absolute Value.
* fabsf: (libc)Absolute Value.
* fabsfN: (libc)Absolute Value.
* fabsfNx: (libc)Absolute Value.
* fabsl: (libc)Absolute Value.
* fadd: (libc)Misc FP Arithmetic.
* faddl: (libc)Misc FP Arithmetic.
* fchdir: (libc)Working Directory.
* fchmod: (libc)Setting Permissions.
* fchown: (libc)File Owner.
* fclose: (libc)Closing Streams.
* fcloseall: (libc)Closing Streams.
* fcntl: (libc)Control Operations.
* fcvt: (libc)System V Number Conversion.
* fcvt_r: (libc)System V Number Conversion.
* fdatasync: (libc)Synchronizing I/O.
* fdim: (libc)Misc FP Arithmetic.
* fdimf: (libc)Misc FP Arithmetic.
* fdimfN: (libc)Misc FP Arithmetic.
* fdimfNx: (libc)Misc FP Arithmetic.
* fdiml: (libc)Misc FP Arithmetic.
* fdiv: (libc)Misc FP Arithmetic.
* fdivl: (libc)Misc FP Arithmetic.
* fdopen: (libc)Descriptors and Streams.
* fdopendir: (libc)Opening a Directory.
* feclearexcept: (libc)Status bit operations.
* fedisableexcept: (libc)Control Functions.
* feenableexcept: (libc)Control Functions.
* fegetenv: (libc)Control Functions.
* fegetexcept: (libc)Control Functions.
* fegetexceptflag: (libc)Status bit operations.
* fegetmode: (libc)Control Functions.
* fegetround: (libc)Rounding.
* feholdexcept: (libc)Control Functions.
* feof: (libc)EOF and Errors.
* feof_unlocked: (libc)EOF and Errors.
* feraiseexcept: (libc)Status bit operations.
* ferror: (libc)EOF and Errors.
* ferror_unlocked: (libc)EOF and Errors.
* fesetenv: (libc)Control Functions.
* fesetexcept: (libc)Status bit operations.
* fesetexceptflag: (libc)Status bit operations.
* fesetmode: (libc)Control Functions.
* fesetround: (libc)Rounding.
* fetestexcept: (libc)Status bit operations.
* fetestexceptflag: (libc)Status bit operations.
* feupdateenv: (libc)Control Functions.
* fexecve: (libc)Executing a File.
* fflush: (libc)Flushing Buffers.
* fflush_unlocked: (libc)Flushing Buffers.
* ffma: (libc)Misc FP Arithmetic.
* ffmal: (libc)Misc FP Arithmetic.
* fgetc: (libc)Character Input.
* fgetc_unlocked: (libc)Character Input.
* fgetgrent: (libc)Scanning All Groups.
* fgetgrent_r: (libc)Scanning All Groups.
* fgetpos64: (libc)Portable Positioning.
* fgetpos: (libc)Portable Positioning.
* fgetpwent: (libc)Scanning All Users.
* fgetpwent_r: (libc)Scanning All Users.
* fgets: (libc)Line Input.
* fgets_unlocked: (libc)Line Input.
* fgetwc: (libc)Character Input.
* fgetwc_unlocked: (libc)Character Input.
* fgetws: (libc)Line Input.
* fgetws_unlocked: (libc)Line Input.
* fileno: (libc)Descriptors and Streams.
* fileno_unlocked: (libc)Descriptors and Streams.
* finite: (libc)Floating Point Classes.
* finitef: (libc)Floating Point Classes.
* finitel: (libc)Floating Point Classes.
* flockfile: (libc)Streams and Threads.
* floor: (libc)Rounding Functions.
* floorf: (libc)Rounding Functions.
* floorfN: (libc)Rounding Functions.
* floorfNx: (libc)Rounding Functions.
* floorl: (libc)Rounding Functions.
* fma: (libc)Misc FP Arithmetic.
* fmaf: (libc)Misc FP Arithmetic.
* fmafN: (libc)Misc FP Arithmetic.
* fmafNx: (libc)Misc FP Arithmetic.
* fmal: (libc)Misc FP Arithmetic.
* fmax: (libc)Misc FP Arithmetic.
* fmaxf: (libc)Misc FP Arithmetic.
* fmaxfN: (libc)Misc FP Arithmetic.
* fmaxfNx: (libc)Misc FP Arithmetic.
* fmaximum: (libc)Misc FP Arithmetic.
* fmaximum_mag: (libc)Misc FP Arithmetic.
* fmaximum_mag_num: (libc)Misc FP Arithmetic.
* fmaximum_mag_numf: (libc)Misc FP Arithmetic.
* fmaximum_mag_numfN: (libc)Misc FP Arithmetic.
* fmaximum_mag_numfNx: (libc)Misc FP Arithmetic.
* fmaximum_mag_numl: (libc)Misc FP Arithmetic.
* fmaximum_magf: (libc)Misc FP Arithmetic.
* fmaximum_magfN: (libc)Misc FP Arithmetic.
* fmaximum_magfNx: (libc)Misc FP Arithmetic.
* fmaximum_magl: (libc)Misc FP Arithmetic.
* fmaximum_num: (libc)Misc FP Arithmetic.
* fmaximum_numf: (libc)Misc FP Arithmetic.
* fmaximum_numfN: (libc)Misc FP Arithmetic.
* fmaximum_numfNx: (libc)Misc FP Arithmetic.
* fmaximum_numl: (libc)Misc FP Arithmetic.
* fmaximumf: (libc)Misc FP Arithmetic.
* fmaximumfN: (libc)Misc FP Arithmetic.
* fmaximumfNx: (libc)Misc FP Arithmetic.
* fmaximuml: (libc)Misc FP Arithmetic.
* fmaxl: (libc)Misc FP Arithmetic.
* fmaxmag: (libc)Misc FP Arithmetic.
* fmaxmagf: (libc)Misc FP Arithmetic.
* fmaxmagfN: (libc)Misc FP Arithmetic.
* fmaxmagfNx: (libc)Misc FP Arithmetic.
* fmaxmagl: (libc)Misc FP Arithmetic.
* fmemopen: (libc)String Streams.
* fmin: (libc)Misc FP Arithmetic.
* fminf: (libc)Misc FP Arithmetic.
* fminfN: (libc)Misc FP Arithmetic.
* fminfNx: (libc)Misc FP Arithmetic.
* fminimum: (libc)Misc FP Arithmetic.
* fminimum_mag: (libc)Misc FP Arithmetic.
* fminimum_mag_num: (libc)Misc FP Arithmetic.
* fminimum_mag_numf: (libc)Misc FP Arithmetic.
* fminimum_mag_numfN: (libc)Misc FP Arithmetic.
* fminimum_mag_numfNx: (libc)Misc FP Arithmetic.
* fminimum_mag_numl: (libc)Misc FP Arithmetic.
* fminimum_magf: (libc)Misc FP Arithmetic.
* fminimum_magfN: (libc)Misc FP Arithmetic.
* fminimum_magfNx: (libc)Misc FP Arithmetic.
* fminimum_magl: (libc)Misc FP Arithmetic.
* fminimum_num: (libc)Misc FP Arithmetic.
* fminimum_numf: (libc)Misc FP Arithmetic.
* fminimum_numfN: (libc)Misc FP Arithmetic.
* fminimum_numfNx: (libc)Misc FP Arithmetic.
* fminimum_numl: (libc)Misc FP Arithmetic.
* fminimumf: (libc)Misc FP Arithmetic.
* fminimumfN: (libc)Misc FP Arithmetic.
* fminimumfNx: (libc)Misc FP Arithmetic.
* fminimuml: (libc)Misc FP Arithmetic.
* fminl: (libc)Misc FP Arithmetic.
* fminmag: (libc)Misc FP Arithmetic.
* fminmagf: (libc)Misc FP Arithmetic.
* fminmagfN: (libc)Misc FP Arithmetic.
* fminmagfNx: (libc)Misc FP Arithmetic.
* fminmagl: (libc)Misc FP Arithmetic.
* fmod: (libc)Remainder Functions.
* fmodf: (libc)Remainder Functions.
* fmodfN: (libc)Remainder Functions.
* fmodfNx: (libc)Remainder Functions.
* fmodl: (libc)Remainder Functions.
* fmtmsg: (libc)Printing Formatted Messages.
* fmul: (libc)Misc FP Arithmetic.
* fmull: (libc)Misc FP Arithmetic.
* fnmatch: (libc)Wildcard Matching.
* fopen64: (libc)Opening Streams.
* fopen: (libc)Opening Streams.
* fopencookie: (libc)Streams and Cookies.
* fork: (libc)Creating a Process.
* forkpty: (libc)Pseudo-Terminal Pairs.
* fpathconf: (libc)Pathconf.
* fpclassify: (libc)Floating Point Classes.
* fprintf: (libc)Formatted Output Functions.
* fputc: (libc)Simple Output.
* fputc_unlocked: (libc)Simple Output.
* fputs: (libc)Simple Output.
* fputs_unlocked: (libc)Simple Output.
* fputwc: (libc)Simple Output.
* fputwc_unlocked: (libc)Simple Output.
* fputws: (libc)Simple Output.
* fputws_unlocked: (libc)Simple Output.
* fread: (libc)Block Input/Output.
* fread_unlocked: (libc)Block Input/Output.
* free: (libc)Freeing after Malloc.
* freopen64: (libc)Opening Streams.
* freopen: (libc)Opening Streams.
* frexp: (libc)Normalization Functions.
* frexpf: (libc)Normalization Functions.
* frexpfN: (libc)Normalization Functions.
* frexpfNx: (libc)Normalization Functions.
* frexpl: (libc)Normalization Functions.
* fromfp: (libc)Rounding Functions.
* fromfpf: (libc)Rounding Functions.
* fromfpfN: (libc)Rounding Functions.
* fromfpfNx: (libc)Rounding Functions.
* fromfpl: (libc)Rounding Functions.
* fromfpx: (libc)Rounding Functions.
* fromfpxf: (libc)Rounding Functions.
* fromfpxfN: (libc)Rounding Functions.
* fromfpxfNx: (libc)Rounding Functions.
* fromfpxl: (libc)Rounding Functions.
* fscanf: (libc)Formatted Input Functions.
* fseek: (libc)File Positioning.
* fseeko64: (libc)File Positioning.
* fseeko: (libc)File Positioning.
* fsetpos64: (libc)Portable Positioning.
* fsetpos: (libc)Portable Positioning.
* fsqrt: (libc)Misc FP Arithmetic.
* fsqrtl: (libc)Misc FP Arithmetic.
* fstat64: (libc)Reading Attributes.
* fstat: (libc)Reading Attributes.
* fsub: (libc)Misc FP Arithmetic.
* fsubl: (libc)Misc FP Arithmetic.
* fsync: (libc)Synchronizing I/O.
* ftell: (libc)File Positioning.
* ftello64: (libc)File Positioning.
* ftello: (libc)File Positioning.
* ftruncate64: (libc)File Size.
* ftruncate: (libc)File Size.
* ftrylockfile: (libc)Streams and Threads.
* ftw64: (libc)Working with Directory Trees.
* ftw: (libc)Working with Directory Trees.
* funlockfile: (libc)Streams and Threads.
* futimes: (libc)File Times.
* fwide: (libc)Streams and I18N.
* fwprintf: (libc)Formatted Output Functions.
* fwrite: (libc)Block Input/Output.
* fwrite_unlocked: (libc)Block Input/Output.
* fwscanf: (libc)Formatted Input Functions.
* gamma: (libc)Special Functions.
* gammaf: (libc)Special Functions.
* gammal: (libc)Special Functions.
* gcvt: (libc)System V Number Conversion.
* get_avphys_pages: (libc)Query Memory Parameters.
* get_current_dir_name: (libc)Working Directory.
* get_nprocs: (libc)Processor Resources.
* get_nprocs_conf: (libc)Processor Resources.
* get_phys_pages: (libc)Query Memory Parameters.
* getauxval: (libc)Auxiliary Vector.
* getc: (libc)Character Input.
* getc_unlocked: (libc)Character Input.
* getchar: (libc)Character Input.
* getchar_unlocked: (libc)Character Input.
* getcontext: (libc)System V contexts.
* getcpu: (libc)CPU Affinity.
* getcwd: (libc)Working Directory.
* getdate: (libc)General Time String Parsing.
* getdate_r: (libc)General Time String Parsing.
* getdelim: (libc)Line Input.
* getdents64: (libc)Low-level Directory Access.
* getdomainnname: (libc)Host Identification.
* getegid: (libc)Reading Persona.
* getentropy: (libc)Unpredictable Bytes.
* getenv: (libc)Environment Access.
* geteuid: (libc)Reading Persona.
* getfsent: (libc)fstab.
* getfsfile: (libc)fstab.
* getfsspec: (libc)fstab.
* getgid: (libc)Reading Persona.
* getgrent: (libc)Scanning All Groups.
* getgrent_r: (libc)Scanning All Groups.
* getgrgid: (libc)Lookup Group.
* getgrgid_r: (libc)Lookup Group.
* getgrnam: (libc)Lookup Group.
* getgrnam_r: (libc)Lookup Group.
* getgrouplist: (libc)Setting Groups.
* getgroups: (libc)Reading Persona.
* gethostbyaddr: (libc)Host Names.
* gethostbyaddr_r: (libc)Host Names.
* gethostbyname2: (libc)Host Names.
* gethostbyname2_r: (libc)Host Names.
* gethostbyname: (libc)Host Names.
* gethostbyname_r: (libc)Host Names.
* gethostent: (libc)Host Names.
* gethostid: (libc)Host Identification.
* gethostname: (libc)Host Identification.
* getitimer: (libc)Setting an Alarm.
* getline: (libc)Line Input.
* getloadavg: (libc)Processor Resources.
* getlogin: (libc)Who Logged In.
* getmntent: (libc)mtab.
* getmntent_r: (libc)mtab.
* getnetbyaddr: (libc)Networks Database.
* getnetbyname: (libc)Networks Database.
* getnetent: (libc)Networks Database.
* getnetgrent: (libc)Lookup Netgroup.
* getnetgrent_r: (libc)Lookup Netgroup.
* getopt: (libc)Using Getopt.
* getopt_long: (libc)Getopt Long Options.
* getopt_long_only: (libc)Getopt Long Options.
* getpagesize: (libc)Query Memory Parameters.
* getpass: (libc)getpass.
* getpayload: (libc)FP Bit Twiddling.
* getpayloadf: (libc)FP Bit Twiddling.
* getpayloadfN: (libc)FP Bit Twiddling.
* getpayloadfNx: (libc)FP Bit Twiddling.
* getpayloadl: (libc)FP Bit Twiddling.
* getpeername: (libc)Who is Connected.
* getpgid: (libc)Process Group Functions.
* getpgrp: (libc)Process Group Functions.
* getpid: (libc)Process Identification.
* getppid: (libc)Process Identification.
* getpriority: (libc)Traditional Scheduling Functions.
* getprotobyname: (libc)Protocols Database.
* getprotobynumber: (libc)Protocols Database.
* getprotoent: (libc)Protocols Database.
* getpt: (libc)Allocation.
* getpwent: (libc)Scanning All Users.
* getpwent_r: (libc)Scanning All Users.
* getpwnam: (libc)Lookup User.
* getpwnam_r: (libc)Lookup User.
* getpwuid: (libc)Lookup User.
* getpwuid_r: (libc)Lookup User.
* getrandom: (libc)Unpredictable Bytes.
* getrlimit64: (libc)Limits on Resources.
* getrlimit: (libc)Limits on Resources.
* getrusage: (libc)Resource Usage.
* gets: (libc)Line Input.
* getservbyname: (libc)Services Database.
* getservbyport: (libc)Services Database.
* getservent: (libc)Services Database.
* getsid: (libc)Process Group Functions.
* getsockname: (libc)Reading Address.
* getsockopt: (libc)Socket Option Functions.
* getsubopt: (libc)Suboptions.
* gettext: (libc)Translation with gettext.
* gettid: (libc)Process Identification.
* gettimeofday: (libc)Getting the Time.
* getuid: (libc)Reading Persona.
* getumask: (libc)Setting Permissions.
* getutent: (libc)Manipulating the Database.
* getutent_r: (libc)Manipulating the Database.
* getutid: (libc)Manipulating the Database.
* getutid_r: (libc)Manipulating the Database.
* getutline: (libc)Manipulating the Database.
* getutline_r: (libc)Manipulating the Database.
* getutmp: (libc)XPG Functions.
* getutmpx: (libc)XPG Functions.
* getutxent: (libc)XPG Functions.
* getutxid: (libc)XPG Functions.
* getutxline: (libc)XPG Functions.
* getw: (libc)Character Input.
* getwc: (libc)Character Input.
* getwc_unlocked: (libc)Character Input.
* getwchar: (libc)Character Input.
* getwchar_unlocked: (libc)Character Input.
* getwd: (libc)Working Directory.
* glob64: (libc)Calling Glob.
* glob: (libc)Calling Glob.
* globfree64: (libc)More Flags for Globbing.
* globfree: (libc)More Flags for Globbing.
* gmtime: (libc)Broken-down Time.
* gmtime_r: (libc)Broken-down Time.
* grantpt: (libc)Allocation.
* gsignal: (libc)Signaling Yourself.
* gtty: (libc)BSD Terminal Modes.
* hasmntopt: (libc)mtab.
* hcreate: (libc)Hash Search Function.
* hcreate_r: (libc)Hash Search Function.
* hdestroy: (libc)Hash Search Function.
* hdestroy_r: (libc)Hash Search Function.
* hsearch: (libc)Hash Search Function.
* hsearch_r: (libc)Hash Search Function.
* htonl: (libc)Byte Order.
* htons: (libc)Byte Order.
* hypot: (libc)Exponents and Logarithms.
* hypotf: (libc)Exponents and Logarithms.
* hypotfN: (libc)Exponents and Logarithms.
* hypotfNx: (libc)Exponents and Logarithms.
* hypotl: (libc)Exponents and Logarithms.
* iconv: (libc)Generic Conversion Interface.
* iconv_close: (libc)Generic Conversion Interface.
* iconv_open: (libc)Generic Conversion Interface.
* if_freenameindex: (libc)Interface Naming.
* if_indextoname: (libc)Interface Naming.
* if_nameindex: (libc)Interface Naming.
* if_nametoindex: (libc)Interface Naming.
* ilogb: (libc)Exponents and Logarithms.
* ilogbf: (libc)Exponents and Logarithms.
* ilogbfN: (libc)Exponents and Logarithms.
* ilogbfNx: (libc)Exponents and Logarithms.
* ilogbl: (libc)Exponents and Logarithms.
* imaxabs: (libc)Absolute Value.
* imaxdiv: (libc)Integer Division.
* in6addr_any: (libc)Host Address Data Type.
* in6addr_loopback: (libc)Host Address Data Type.
* index: (libc)Search Functions.
* inet_addr: (libc)Host Address Functions.
* inet_aton: (libc)Host Address Functions.
* inet_lnaof: (libc)Host Address Functions.
* inet_makeaddr: (libc)Host Address Functions.
* inet_netof: (libc)Host Address Functions.
* inet_network: (libc)Host Address Functions.
* inet_ntoa: (libc)Host Address Functions.
* inet_ntop: (libc)Host Address Functions.
* inet_pton: (libc)Host Address Functions.
* initgroups: (libc)Setting Groups.
* initstate: (libc)BSD Random.
* initstate_r: (libc)BSD Random.
* innetgr: (libc)Netgroup Membership.
* ioctl: (libc)IOCTLs.
* isalnum: (libc)Classification of Characters.
* isalpha: (libc)Classification of Characters.
* isascii: (libc)Classification of Characters.
* isatty: (libc)Is It a Terminal.
* isblank: (libc)Classification of Characters.
* iscanonical: (libc)Floating Point Classes.
* iscntrl: (libc)Classification of Characters.
* isdigit: (libc)Classification of Characters.
* iseqsig: (libc)FP Comparison Functions.
* isfinite: (libc)Floating Point Classes.
* isgraph: (libc)Classification of Characters.
* isgreater: (libc)FP Comparison Functions.
* isgreaterequal: (libc)FP Comparison Functions.
* isinf: (libc)Floating Point Classes.
* isinff: (libc)Floating Point Classes.
* isinfl: (libc)Floating Point Classes.
* isless: (libc)FP Comparison Functions.
* islessequal: (libc)FP Comparison Functions.
* islessgreater: (libc)FP Comparison Functions.
* islower: (libc)Classification of Characters.
* isnan: (libc)Floating Point Classes.
* isnan: (libc)Floating Point Classes.
* isnanf: (libc)Floating Point Classes.
* isnanl: (libc)Floating Point Classes.
* isnormal: (libc)Floating Point Classes.
* isprint: (libc)Classification of Characters.
* ispunct: (libc)Classification of Characters.
* issignaling: (libc)Floating Point Classes.
* isspace: (libc)Classification of Characters.
* issubnormal: (libc)Floating Point Classes.
* isunordered: (libc)FP Comparison Functions.
* isupper: (libc)Classification of Characters.
* iswalnum: (libc)Classification of Wide Characters.
* iswalpha: (libc)Classification of Wide Characters.
* iswblank: (libc)Classification of Wide Characters.
* iswcntrl: (libc)Classification of Wide Characters.
* iswctype: (libc)Classification of Wide Characters.
* iswdigit: (libc)Classification of Wide Characters.
* iswgraph: (libc)Classification of Wide Characters.
* iswlower: (libc)Classification of Wide Characters.
* iswprint: (libc)Classification of Wide Characters.
* iswpunct: (libc)Classification of Wide Characters.
* iswspace: (libc)Classification of Wide Characters.
* iswupper: (libc)Classification of Wide Characters.
* iswxdigit: (libc)Classification of Wide Characters.
* isxdigit: (libc)Classification of Characters.
* iszero: (libc)Floating Point Classes.
* j0: (libc)Special Functions.
* j0f: (libc)Special Functions.
* j0fN: (libc)Special Functions.
* j0fNx: (libc)Special Functions.
* j0l: (libc)Special Functions.
* j1: (libc)Special Functions.
* j1f: (libc)Special Functions.
* j1fN: (libc)Special Functions.
* j1fNx: (libc)Special Functions.
* j1l: (libc)Special Functions.
* jn: (libc)Special Functions.
* jnf: (libc)Special Functions.
* jnfN: (libc)Special Functions.
* jnfNx: (libc)Special Functions.
* jnl: (libc)Special Functions.
* jrand48: (libc)SVID Random.
* jrand48_r: (libc)SVID Random.
* kill: (libc)Signaling Another Process.
* killpg: (libc)Signaling Another Process.
* l64a: (libc)Encode Binary Data.
* labs: (libc)Absolute Value.
* lcong48: (libc)SVID Random.
* lcong48_r: (libc)SVID Random.
* ldexp: (libc)Normalization Functions.
* ldexpf: (libc)Normalization Functions.
* ldexpfN: (libc)Normalization Functions.
* ldexpfNx: (libc)Normalization Functions.
* ldexpl: (libc)Normalization Functions.
* ldiv: (libc)Integer Division.
* lfind: (libc)Array Search Function.
* lgamma: (libc)Special Functions.
* lgamma_r: (libc)Special Functions.
* lgammaf: (libc)Special Functions.
* lgammafN: (libc)Special Functions.
* lgammafN_r: (libc)Special Functions.
* lgammafNx: (libc)Special Functions.
* lgammafNx_r: (libc)Special Functions.
* lgammaf_r: (libc)Special Functions.
* lgammal: (libc)Special Functions.
* lgammal_r: (libc)Special Functions.
* link: (libc)Hard Links.
* linkat: (libc)Hard Links.
* lio_listio64: (libc)Asynchronous Reads/Writes.
* lio_listio: (libc)Asynchronous Reads/Writes.
* listen: (libc)Listening.
* llabs: (libc)Absolute Value.
* lldiv: (libc)Integer Division.
* llogb: (libc)Exponents and Logarithms.
* llogbf: (libc)Exponents and Logarithms.
* llogbfN: (libc)Exponents and Logarithms.
* llogbfNx: (libc)Exponents and Logarithms.
* llogbl: (libc)Exponents and Logarithms.
* llrint: (libc)Rounding Functions.
* llrintf: (libc)Rounding Functions.
* llrintfN: (libc)Rounding Functions.
* llrintfNx: (libc)Rounding Functions.
* llrintl: (libc)Rounding Functions.
* llround: (libc)Rounding Functions.
* llroundf: (libc)Rounding Functions.
* llroundfN: (libc)Rounding Functions.
* llroundfNx: (libc)Rounding Functions.
* llroundl: (libc)Rounding Functions.
* localeconv: (libc)The Lame Way to Locale Data.
* localtime: (libc)Broken-down Time.
* localtime_r: (libc)Broken-down Time.
* log10: (libc)Exponents and Logarithms.
* log10f: (libc)Exponents and Logarithms.
* log10fN: (libc)Exponents and Logarithms.
* log10fNx: (libc)Exponents and Logarithms.
* log10l: (libc)Exponents and Logarithms.
* log1p: (libc)Exponents and Logarithms.
* log1pf: (libc)Exponents and Logarithms.
* log1pfN: (libc)Exponents and Logarithms.
* log1pfNx: (libc)Exponents and Logarithms.
* log1pl: (libc)Exponents and Logarithms.
* log2: (libc)Exponents and Logarithms.
* log2f: (libc)Exponents and Logarithms.
* log2fN: (libc)Exponents and Logarithms.
* log2fNx: (libc)Exponents and Logarithms.
* log2l: (libc)Exponents and Logarithms.
* log: (libc)Exponents and Logarithms.
* logb: (libc)Exponents and Logarithms.
* logbf: (libc)Exponents and Logarithms.
* logbfN: (libc)Exponents and Logarithms.
* logbfNx: (libc)Exponents and Logarithms.
* logbl: (libc)Exponents and Logarithms.
* logf: (libc)Exponents and Logarithms.
* logfN: (libc)Exponents and Logarithms.
* logfNx: (libc)Exponents and Logarithms.
* login: (libc)Logging In and Out.
* login_tty: (libc)Logging In and Out.
* logl: (libc)Exponents and Logarithms.
* logout: (libc)Logging In and Out.
* logwtmp: (libc)Logging In and Out.
* longjmp: (libc)Non-Local Details.
* lrand48: (libc)SVID Random.
* lrand48_r: (libc)SVID Random.
* lrint: (libc)Rounding Functions.
* lrintf: (libc)Rounding Functions.
* lrintfN: (libc)Rounding Functions.
* lrintfNx: (libc)Rounding Functions.
* lrintl: (libc)Rounding Functions.
* lround: (libc)Rounding Functions.
* lroundf: (libc)Rounding Functions.
* lroundfN: (libc)Rounding Functions.
* lroundfNx: (libc)Rounding Functions.
* lroundl: (libc)Rounding Functions.
* lsearch: (libc)Array Search Function.
* lseek64: (libc)File Position Primitive.
* lseek: (libc)File Position Primitive.
* lstat64: (libc)Reading Attributes.
* lstat: (libc)Reading Attributes.
* lutimes: (libc)File Times.
* madvise: (libc)Memory-mapped I/O.
* makecontext: (libc)System V contexts.
* mallinfo2: (libc)Statistics of Malloc.
* malloc: (libc)Basic Allocation.
* mallopt: (libc)Malloc Tunable Parameters.
* mblen: (libc)Non-reentrant Character Conversion.
* mbrlen: (libc)Converting a Character.
* mbrtowc: (libc)Converting a Character.
* mbsinit: (libc)Keeping the state.
* mbsnrtowcs: (libc)Converting Strings.
* mbsrtowcs: (libc)Converting Strings.
* mbstowcs: (libc)Non-reentrant String Conversion.
* mbtowc: (libc)Non-reentrant Character Conversion.
* mcheck: (libc)Heap Consistency Checking.
* memalign: (libc)Aligned Memory Blocks.
* memccpy: (libc)Copying Strings and Arrays.
* memchr: (libc)Search Functions.
* memcmp: (libc)String/Array Comparison.
* memcpy: (libc)Copying Strings and Arrays.
* memfd_create: (libc)Memory-mapped I/O.
* memfrob: (libc)Obfuscating Data.
* memmem: (libc)Search Functions.
* memmove: (libc)Copying Strings and Arrays.
* mempcpy: (libc)Copying Strings and Arrays.
* memrchr: (libc)Search Functions.
* memset: (libc)Copying Strings and Arrays.
* mkdir: (libc)Creating Directories.
* mkdtemp: (libc)Temporary Files.
* mkfifo: (libc)FIFO Special Files.
* mknod: (libc)Making Special Files.
* mkstemp: (libc)Temporary Files.
* mktemp: (libc)Temporary Files.
* mktime: (libc)Broken-down Time.
* mlock2: (libc)Page Lock Functions.
* mlock: (libc)Page Lock Functions.
* mlockall: (libc)Page Lock Functions.
* mmap64: (libc)Memory-mapped I/O.
* mmap: (libc)Memory-mapped I/O.
* modf: (libc)Rounding Functions.
* modff: (libc)Rounding Functions.
* modffN: (libc)Rounding Functions.
* modffNx: (libc)Rounding Functions.
* modfl: (libc)Rounding Functions.
* mount: (libc)Mount-Unmount-Remount.
* mprobe: (libc)Heap Consistency Checking.
* mprotect: (libc)Memory Protection.
* mrand48: (libc)SVID Random.
* mrand48_r: (libc)SVID Random.
* mremap: (libc)Memory-mapped I/O.
* msync: (libc)Memory-mapped I/O.
* mtrace: (libc)Tracing malloc.
* mtx_destroy: (libc)ISO C Mutexes.
* mtx_init: (libc)ISO C Mutexes.
* mtx_lock: (libc)ISO C Mutexes.
* mtx_timedlock: (libc)ISO C Mutexes.
* mtx_trylock: (libc)ISO C Mutexes.
* mtx_unlock: (libc)ISO C Mutexes.
* munlock: (libc)Page Lock Functions.
* munlockall: (libc)Page Lock Functions.
* munmap: (libc)Memory-mapped I/O.
* muntrace: (libc)Tracing malloc.
* nan: (libc)FP Bit Twiddling.
* nanf: (libc)FP Bit Twiddling.
* nanfN: (libc)FP Bit Twiddling.
* nanfNx: (libc)FP Bit Twiddling.
* nanl: (libc)FP Bit Twiddling.
* nanosleep: (libc)Sleeping.
* nearbyint: (libc)Rounding Functions.
* nearbyintf: (libc)Rounding Functions.
* nearbyintfN: (libc)Rounding Functions.
* nearbyintfNx: (libc)Rounding Functions.
* nearbyintl: (libc)Rounding Functions.
* nextafter: (libc)FP Bit Twiddling.
* nextafterf: (libc)FP Bit Twiddling.
* nextafterfN: (libc)FP Bit Twiddling.
* nextafterfNx: (libc)FP Bit Twiddling.
* nextafterl: (libc)FP Bit Twiddling.
* nextdown: (libc)FP Bit Twiddling.
* nextdownf: (libc)FP Bit Twiddling.
* nextdownfN: (libc)FP Bit Twiddling.
* nextdownfNx: (libc)FP Bit Twiddling.
* nextdownl: (libc)FP Bit Twiddling.
* nexttoward: (libc)FP Bit Twiddling.
* nexttowardf: (libc)FP Bit Twiddling.
* nexttowardl: (libc)FP Bit Twiddling.
* nextup: (libc)FP Bit Twiddling.
* nextupf: (libc)FP Bit Twiddling.
* nextupfN: (libc)FP Bit Twiddling.
* nextupfNx: (libc)FP Bit Twiddling.
* nextupl: (libc)FP Bit Twiddling.
* nftw64: (libc)Working with Directory Trees.
* nftw: (libc)Working with Directory Trees.
* ngettext: (libc)Advanced gettext functions.
* nice: (libc)Traditional Scheduling Functions.
* nl_langinfo: (libc)The Elegant and Fast Way.
* nrand48: (libc)SVID Random.
* nrand48_r: (libc)SVID Random.
* ntohl: (libc)Byte Order.
* ntohs: (libc)Byte Order.
* ntp_adjtime: (libc)Setting and Adjusting the Time.
* ntp_gettime: (libc)Setting and Adjusting the Time.
* obstack_1grow: (libc)Growing Objects.
* obstack_1grow_fast: (libc)Extra Fast Growing.
* obstack_alignment_mask: (libc)Obstacks Data Alignment.
* obstack_alloc: (libc)Allocation in an Obstack.
* obstack_base: (libc)Status of an Obstack.
* obstack_blank: (libc)Growing Objects.
* obstack_blank_fast: (libc)Extra Fast Growing.
* obstack_chunk_size: (libc)Obstack Chunks.
* obstack_copy0: (libc)Allocation in an Obstack.
* obstack_copy: (libc)Allocation in an Obstack.
* obstack_finish: (libc)Growing Objects.
* obstack_free: (libc)Freeing Obstack Objects.
* obstack_grow0: (libc)Growing Objects.
* obstack_grow: (libc)Growing Objects.
* obstack_init: (libc)Preparing for Obstacks.
* obstack_int_grow: (libc)Growing Objects.
* obstack_int_grow_fast: (libc)Extra Fast Growing.
* obstack_next_free: (libc)Status of an Obstack.
* obstack_object_size: (libc)Growing Objects.
* obstack_object_size: (libc)Status of an Obstack.
* obstack_printf: (libc)Dynamic Output.
* obstack_ptr_grow: (libc)Growing Objects.
* obstack_ptr_grow_fast: (libc)Extra Fast Growing.
* obstack_room: (libc)Extra Fast Growing.
* obstack_vprintf: (libc)Variable Arguments Output.
* offsetof: (libc)Structure Measurement.
* on_exit: (libc)Cleanups on Exit.
* open64: (libc)Opening and Closing Files.
* open: (libc)Opening and Closing Files.
* open_memstream: (libc)String Streams.
* opendir: (libc)Opening a Directory.
* openlog: (libc)openlog.
* openpty: (libc)Pseudo-Terminal Pairs.
* parse_printf_format: (libc)Parsing a Template String.
* pathconf: (libc)Pathconf.
* pause: (libc)Using Pause.
* pclose: (libc)Pipe to a Subprocess.
* perror: (libc)Error Messages.
* pipe: (libc)Creating a Pipe.
* pkey_alloc: (libc)Memory Protection.
* pkey_free: (libc)Memory Protection.
* pkey_get: (libc)Memory Protection.
* pkey_mprotect: (libc)Memory Protection.
* pkey_set: (libc)Memory Protection.
* popen: (libc)Pipe to a Subprocess.
* posix_fallocate64: (libc)Storage Allocation.
* posix_fallocate: (libc)Storage Allocation.
* posix_memalign: (libc)Aligned Memory Blocks.
* pow: (libc)Exponents and Logarithms.
* powf: (libc)Exponents and Logarithms.
* powfN: (libc)Exponents and Logarithms.
* powfNx: (libc)Exponents and Logarithms.
* powl: (libc)Exponents and Logarithms.
* pread64: (libc)I/O Primitives.
* pread: (libc)I/O Primitives.
* preadv2: (libc)Scatter-Gather.
* preadv64: (libc)Scatter-Gather.
* preadv64v2: (libc)Scatter-Gather.
* preadv: (libc)Scatter-Gather.
* printf: (libc)Formatted Output Functions.
* printf_size: (libc)Predefined Printf Handlers.
* printf_size_info: (libc)Predefined Printf Handlers.
* psignal: (libc)Signal Messages.
* pthread_attr_getsigmask_np: (libc)Initial Thread Signal Mask.
* pthread_attr_setsigmask_np: (libc)Initial Thread Signal Mask.
* pthread_clockjoin_np: (libc)Waiting with Explicit Clocks.
* pthread_cond_clockwait: (libc)Waiting with Explicit Clocks.
* pthread_getattr_default_np: (libc)Default Thread Attributes.
* pthread_getspecific: (libc)Thread-specific Data.
* pthread_key_create: (libc)Thread-specific Data.
* pthread_key_delete: (libc)Thread-specific Data.
* pthread_rwlock_clockrdlock: (libc)Waiting with Explicit Clocks.
* pthread_rwlock_clockwrlock: (libc)Waiting with Explicit Clocks.
* pthread_setattr_default_np: (libc)Default Thread Attributes.
* pthread_setspecific: (libc)Thread-specific Data.
* pthread_timedjoin_np: (libc)Waiting with Explicit Clocks.
* pthread_tryjoin_np: (libc)Waiting with Explicit Clocks.
* ptsname: (libc)Allocation.
* ptsname_r: (libc)Allocation.
* putc: (libc)Simple Output.
* putc_unlocked: (libc)Simple Output.
* putchar: (libc)Simple Output.
* putchar_unlocked: (libc)Simple Output.
* putenv: (libc)Environment Access.
* putpwent: (libc)Writing a User Entry.
* puts: (libc)Simple Output.
* pututline: (libc)Manipulating the Database.
* pututxline: (libc)XPG Functions.
* putw: (libc)Simple Output.
* putwc: (libc)Simple Output.
* putwc_unlocked: (libc)Simple Output.
* putwchar: (libc)Simple Output.
* putwchar_unlocked: (libc)Simple Output.
* pwrite64: (libc)I/O Primitives.
* pwrite: (libc)I/O Primitives.
* pwritev2: (libc)Scatter-Gather.
* pwritev64: (libc)Scatter-Gather.
* pwritev64v2: (libc)Scatter-Gather.
* pwritev: (libc)Scatter-Gather.
* qecvt: (libc)System V Number Conversion.
* qecvt_r: (libc)System V Number Conversion.
* qfcvt: (libc)System V Number Conversion.
* qfcvt_r: (libc)System V Number Conversion.
* qgcvt: (libc)System V Number Conversion.
* qsort: (libc)Array Sort Function.
* raise: (libc)Signaling Yourself.
* rand: (libc)ISO Random.
* rand_r: (libc)ISO Random.
* random: (libc)BSD Random.
* random_r: (libc)BSD Random.
* rawmemchr: (libc)Search Functions.
* read: (libc)I/O Primitives.
* readdir64: (libc)Reading/Closing Directory.
* readdir64_r: (libc)Reading/Closing Directory.
* readdir: (libc)Reading/Closing Directory.
* readdir_r: (libc)Reading/Closing Directory.
* readlink: (libc)Symbolic Links.
* readv: (libc)Scatter-Gather.
* realloc: (libc)Changing Block Size.
* reallocarray: (libc)Changing Block Size.
* realpath: (libc)Symbolic Links.
* recv: (libc)Receiving Data.
* recvfrom: (libc)Receiving Datagrams.
* recvmsg: (libc)Receiving Datagrams.
* regcomp: (libc)POSIX Regexp Compilation.
* regerror: (libc)Regexp Cleanup.
* regexec: (libc)Matching POSIX Regexps.
* regfree: (libc)Regexp Cleanup.
* register_printf_function: (libc)Registering New Conversions.
* remainder: (libc)Remainder Functions.
* remainderf: (libc)Remainder Functions.
* remainderfN: (libc)Remainder Functions.
* remainderfNx: (libc)Remainder Functions.
* remainderl: (libc)Remainder Functions.
* remove: (libc)Deleting Files.
* rename: (libc)Renaming Files.
* rewind: (libc)File Positioning.
* rewinddir: (libc)Random Access Directory.
* rindex: (libc)Search Functions.
* rint: (libc)Rounding Functions.
* rintf: (libc)Rounding Functions.
* rintfN: (libc)Rounding Functions.
* rintfNx: (libc)Rounding Functions.
* rintl: (libc)Rounding Functions.
* rmdir: (libc)Deleting Files.
* round: (libc)Rounding Functions.
* roundeven: (libc)Rounding Functions.
* roundevenf: (libc)Rounding Functions.
* roundevenfN: (libc)Rounding Functions.
* roundevenfNx: (libc)Rounding Functions.
* roundevenl: (libc)Rounding Functions.
* roundf: (libc)Rounding Functions.
* roundfN: (libc)Rounding Functions.
* roundfNx: (libc)Rounding Functions.
* roundl: (libc)Rounding Functions.
* rpmatch: (libc)Yes-or-No Questions.
* sbrk: (libc)Resizing the Data Segment.
* scalb: (libc)Normalization Functions.
* scalbf: (libc)Normalization Functions.
* scalbl: (libc)Normalization Functions.
* scalbln: (libc)Normalization Functions.
* scalblnf: (libc)Normalization Functions.
* scalblnfN: (libc)Normalization Functions.
* scalblnfNx: (libc)Normalization Functions.
* scalblnl: (libc)Normalization Functions.
* scalbn: (libc)Normalization Functions.
* scalbnf: (libc)Normalization Functions.
* scalbnfN: (libc)Normalization Functions.
* scalbnfNx: (libc)Normalization Functions.
* scalbnl: (libc)Normalization Functions.
* scandir64: (libc)Scanning Directory Content.
* scandir: (libc)Scanning Directory Content.
* scanf: (libc)Formatted Input Functions.
* sched_get_priority_max: (libc)Basic Scheduling Functions.
* sched_get_priority_min: (libc)Basic Scheduling Functions.
* sched_getaffinity: (libc)CPU Affinity.
* sched_getparam: (libc)Basic Scheduling Functions.
* sched_getscheduler: (libc)Basic Scheduling Functions.
* sched_rr_get_interval: (libc)Basic Scheduling Functions.
* sched_setaffinity: (libc)CPU Affinity.
* sched_setparam: (libc)Basic Scheduling Functions.
* sched_setscheduler: (libc)Basic Scheduling Functions.
* sched_yield: (libc)Basic Scheduling Functions.
* secure_getenv: (libc)Environment Access.
* seed48: (libc)SVID Random.
* seed48_r: (libc)SVID Random.
* seekdir: (libc)Random Access Directory.
* select: (libc)Waiting for I/O.
* sem_clockwait: (libc)Waiting with Explicit Clocks.
* sem_close: (libc)Semaphores.
* sem_destroy: (libc)Semaphores.
* sem_getvalue: (libc)Semaphores.
* sem_init: (libc)Semaphores.
* sem_open: (libc)Semaphores.
* sem_post: (libc)Semaphores.
* sem_timedwait: (libc)Semaphores.
* sem_trywait: (libc)Semaphores.
* sem_unlink: (libc)Semaphores.
* sem_wait: (libc)Semaphores.
* semctl: (libc)Semaphores.
* semget: (libc)Semaphores.
* semop: (libc)Semaphores.
* semtimedop: (libc)Semaphores.
* send: (libc)Sending Data.
* sendmsg: (libc)Receiving Datagrams.
* sendto: (libc)Sending Datagrams.
* setbuf: (libc)Controlling Buffering.
* setbuffer: (libc)Controlling Buffering.
* setcontext: (libc)System V contexts.
* setdomainname: (libc)Host Identification.
* setegid: (libc)Setting Groups.
* setenv: (libc)Environment Access.
* seteuid: (libc)Setting User ID.
* setfsent: (libc)fstab.
* setgid: (libc)Setting Groups.
* setgrent: (libc)Scanning All Groups.
* setgroups: (libc)Setting Groups.
* sethostent: (libc)Host Names.
* sethostid: (libc)Host Identification.
* sethostname: (libc)Host Identification.
* setitimer: (libc)Setting an Alarm.
* setjmp: (libc)Non-Local Details.
* setlinebuf: (libc)Controlling Buffering.
* setlocale: (libc)Setting the Locale.
* setlogmask: (libc)setlogmask.
* setmntent: (libc)mtab.
* setnetent: (libc)Networks Database.
* setnetgrent: (libc)Lookup Netgroup.
* setpayload: (libc)FP Bit Twiddling.
* setpayloadf: (libc)FP Bit Twiddling.
* setpayloadfN: (libc)FP Bit Twiddling.
* setpayloadfNx: (libc)FP Bit Twiddling.
* setpayloadl: (libc)FP Bit Twiddling.
* setpayloadsig: (libc)FP Bit Twiddling.
* setpayloadsigf: (libc)FP Bit Twiddling.
* setpayloadsigfN: (libc)FP Bit Twiddling.
* setpayloadsigfNx: (libc)FP Bit Twiddling.
* setpayloadsigl: (libc)FP Bit Twiddling.
* setpgid: (libc)Process Group Functions.
* setpgrp: (libc)Process Group Functions.
* setpriority: (libc)Traditional Scheduling Functions.
* setprotoent: (libc)Protocols Database.
* setpwent: (libc)Scanning All Users.
* setregid: (libc)Setting Groups.
* setreuid: (libc)Setting User ID.
* setrlimit64: (libc)Limits on Resources.
* setrlimit: (libc)Limits on Resources.
* setservent: (libc)Services Database.
* setsid: (libc)Process Group Functions.
* setsockopt: (libc)Socket Option Functions.
* setstate: (libc)BSD Random.
* setstate_r: (libc)BSD Random.
* settimeofday: (libc)Setting and Adjusting the Time.
* setuid: (libc)Setting User ID.
* setutent: (libc)Manipulating the Database.
* setutxent: (libc)XPG Functions.
* setvbuf: (libc)Controlling Buffering.
* shm_open: (libc)Memory-mapped I/O.
* shm_unlink: (libc)Memory-mapped I/O.
* shutdown: (libc)Closing a Socket.
* sigabbrev_np: (libc)Signal Messages.
* sigaction: (libc)Advanced Signal Handling.
* sigaddset: (libc)Signal Sets.
* sigaltstack: (libc)Signal Stack.
* sigblock: (libc)BSD Signal Handling.
* sigdelset: (libc)Signal Sets.
* sigdescr_np: (libc)Signal Messages.
* sigemptyset: (libc)Signal Sets.
* sigfillset: (libc)Signal Sets.
* siginterrupt: (libc)BSD Signal Handling.
* sigismember: (libc)Signal Sets.
* siglongjmp: (libc)Non-Local Exits and Signals.
* sigmask: (libc)BSD Signal Handling.
* signal: (libc)Basic Signal Handling.
* signbit: (libc)FP Bit Twiddling.
* significand: (libc)Normalization Functions.
* significandf: (libc)Normalization Functions.
* significandl: (libc)Normalization Functions.
* sigpause: (libc)BSD Signal Handling.
* sigpending: (libc)Checking for Pending Signals.
* sigprocmask: (libc)Process Signal Mask.
* sigsetjmp: (libc)Non-Local Exits and Signals.
* sigsetmask: (libc)BSD Signal Handling.
* sigstack: (libc)Signal Stack.
* sigsuspend: (libc)Sigsuspend.
* sin: (libc)Trig Functions.
* sincos: (libc)Trig Functions.
* sincosf: (libc)Trig Functions.
* sincosfN: (libc)Trig Functions.
* sincosfNx: (libc)Trig Functions.
* sincosl: (libc)Trig Functions.
* sinf: (libc)Trig Functions.
* sinfN: (libc)Trig Functions.
* sinfNx: (libc)Trig Functions.
* sinh: (libc)Hyperbolic Functions.
* sinhf: (libc)Hyperbolic Functions.
* sinhfN: (libc)Hyperbolic Functions.
* sinhfNx: (libc)Hyperbolic Functions.
* sinhl: (libc)Hyperbolic Functions.
* sinl: (libc)Trig Functions.
* sleep: (libc)Sleeping.
* snprintf: (libc)Formatted Output Functions.
* socket: (libc)Creating a Socket.
* socketpair: (libc)Socket Pairs.
* sprintf: (libc)Formatted Output Functions.
* sqrt: (libc)Exponents and Logarithms.
* sqrtf: (libc)Exponents and Logarithms.
* sqrtfN: (libc)Exponents and Logarithms.
* sqrtfNx: (libc)Exponents and Logarithms.
* sqrtl: (libc)Exponents and Logarithms.
* srand48: (libc)SVID Random.
* srand48_r: (libc)SVID Random.
* srand: (libc)ISO Random.
* srandom: (libc)BSD Random.
* srandom_r: (libc)BSD Random.
* sscanf: (libc)Formatted Input Functions.
* ssignal: (libc)Basic Signal Handling.
* stat64: (libc)Reading Attributes.
* stat: (libc)Reading Attributes.
* stime: (libc)Setting and Adjusting the Time.
* stpcpy: (libc)Copying Strings and Arrays.
* stpncpy: (libc)Truncating Strings.
* strcasecmp: (libc)String/Array Comparison.
* strcasestr: (libc)Search Functions.
* strcat: (libc)Concatenating Strings.
* strchr: (libc)Search Functions.
* strchrnul: (libc)Search Functions.
* strcmp: (libc)String/Array Comparison.
* strcoll: (libc)Collation Functions.
* strcpy: (libc)Copying Strings and Arrays.
* strcspn: (libc)Search Functions.
* strdup: (libc)Copying Strings and Arrays.
* strdupa: (libc)Copying Strings and Arrays.
* strerror: (libc)Error Messages.
* strerror_r: (libc)Error Messages.
* strerrordesc_np: (libc)Error Messages.
* strerrorname_np: (libc)Error Messages.
* strfmon: (libc)Formatting Numbers.
* strfromd: (libc)Printing of Floats.
* strfromf: (libc)Printing of Floats.
* strfromfN: (libc)Printing of Floats.
* strfromfNx: (libc)Printing of Floats.
* strfroml: (libc)Printing of Floats.
* strfry: (libc)Shuffling Bytes.
* strftime: (libc)Formatting Calendar Time.
* strlen: (libc)String Length.
* strncasecmp: (libc)String/Array Comparison.
* strncat: (libc)Truncating Strings.
* strncmp: (libc)String/Array Comparison.
* strncpy: (libc)Truncating Strings.
* strndup: (libc)Truncating Strings.
* strndupa: (libc)Truncating Strings.
* strnlen: (libc)String Length.
* strpbrk: (libc)Search Functions.
* strptime: (libc)Low-Level Time String Parsing.
* strrchr: (libc)Search Functions.
* strsep: (libc)Finding Tokens in a String.
* strsignal: (libc)Signal Messages.
* strspn: (libc)Search Functions.
* strstr: (libc)Search Functions.
* strtod: (libc)Parsing of Floats.
* strtof: (libc)Parsing of Floats.
* strtofN: (libc)Parsing of Floats.
* strtofNx: (libc)Parsing of Floats.
* strtoimax: (libc)Parsing of Integers.
* strtok: (libc)Finding Tokens in a String.
* strtok_r: (libc)Finding Tokens in a String.
* strtol: (libc)Parsing of Integers.
* strtold: (libc)Parsing of Floats.
* strtoll: (libc)Parsing of Integers.
* strtoq: (libc)Parsing of Integers.
* strtoul: (libc)Parsing of Integers.
* strtoull: (libc)Parsing of Integers.
* strtoumax: (libc)Parsing of Integers.
* strtouq: (libc)Parsing of Integers.
* strverscmp: (libc)String/Array Comparison.
* strxfrm: (libc)Collation Functions.
* stty: (libc)BSD Terminal Modes.
* swapcontext: (libc)System V contexts.
* swprintf: (libc)Formatted Output Functions.
* swscanf: (libc)Formatted Input Functions.
* symlink: (libc)Symbolic Links.
* sync: (libc)Synchronizing I/O.
* syscall: (libc)System Calls.
* sysconf: (libc)Sysconf Definition.
* syslog: (libc)syslog; vsyslog.
* system: (libc)Running a Command.
* sysv_signal: (libc)Basic Signal Handling.
* tan: (libc)Trig Functions.
* tanf: (libc)Trig Functions.
* tanfN: (libc)Trig Functions.
* tanfNx: (libc)Trig Functions.
* tanh: (libc)Hyperbolic Functions.
* tanhf: (libc)Hyperbolic Functions.
* tanhfN: (libc)Hyperbolic Functions.
* tanhfNx: (libc)Hyperbolic Functions.
* tanhl: (libc)Hyperbolic Functions.
* tanl: (libc)Trig Functions.
* tcdrain: (libc)Line Control.
* tcflow: (libc)Line Control.
* tcflush: (libc)Line Control.
* tcgetattr: (libc)Mode Functions.
* tcgetpgrp: (libc)Terminal Access Functions.
* tcgetsid: (libc)Terminal Access Functions.
* tcsendbreak: (libc)Line Control.
* tcsetattr: (libc)Mode Functions.
* tcsetpgrp: (libc)Terminal Access Functions.
* tdelete: (libc)Tree Search Function.
* tdestroy: (libc)Tree Search Function.
* telldir: (libc)Random Access Directory.
* tempnam: (libc)Temporary Files.
* textdomain: (libc)Locating gettext catalog.
* tfind: (libc)Tree Search Function.
* tgamma: (libc)Special Functions.
* tgammaf: (libc)Special Functions.
* tgammafN: (libc)Special Functions.
* tgammafNx: (libc)Special Functions.
* tgammal: (libc)Special Functions.
* tgkill: (libc)Signaling Another Process.
* thrd_create: (libc)ISO C Thread Management.
* thrd_current: (libc)ISO C Thread Management.
* thrd_detach: (libc)ISO C Thread Management.
* thrd_equal: (libc)ISO C Thread Management.
* thrd_exit: (libc)ISO C Thread Management.
* thrd_join: (libc)ISO C Thread Management.
* thrd_sleep: (libc)ISO C Thread Management.
* thrd_yield: (libc)ISO C Thread Management.
* time: (libc)Getting the Time.
* timegm: (libc)Broken-down Time.
* timelocal: (libc)Broken-down Time.
* times: (libc)Processor Time.
* tmpfile64: (libc)Temporary Files.
* tmpfile: (libc)Temporary Files.
* tmpnam: (libc)Temporary Files.
* tmpnam_r: (libc)Temporary Files.
* toascii: (libc)Case Conversion.
* tolower: (libc)Case Conversion.
* totalorder: (libc)FP Comparison Functions.
* totalorderf: (libc)FP Comparison Functions.
* totalorderfN: (libc)FP Comparison Functions.
* totalorderfNx: (libc)FP Comparison Functions.
* totalorderl: (libc)FP Comparison Functions.
* totalordermag: (libc)FP Comparison Functions.
* totalordermagf: (libc)FP Comparison Functions.
* totalordermagfN: (libc)FP Comparison Functions.
* totalordermagfNx: (libc)FP Comparison Functions.
* totalordermagl: (libc)FP Comparison Functions.
* toupper: (libc)Case Conversion.
* towctrans: (libc)Wide Character Case Conversion.
* towlower: (libc)Wide Character Case Conversion.
* towupper: (libc)Wide Character Case Conversion.
* trunc: (libc)Rounding Functions.
* truncate64: (libc)File Size.
* truncate: (libc)File Size.
* truncf: (libc)Rounding Functions.
* truncfN: (libc)Rounding Functions.
* truncfNx: (libc)Rounding Functions.
* truncl: (libc)Rounding Functions.
* tsearch: (libc)Tree Search Function.
* tss_create: (libc)ISO C Thread-local Storage.
* tss_delete: (libc)ISO C Thread-local Storage.
* tss_get: (libc)ISO C Thread-local Storage.
* tss_set: (libc)ISO C Thread-local Storage.
* ttyname: (libc)Is It a Terminal.
* ttyname_r: (libc)Is It a Terminal.
* twalk: (libc)Tree Search Function.
* twalk_r: (libc)Tree Search Function.
* tzset: (libc)Time Zone Functions.
* ufromfp: (libc)Rounding Functions.
* ufromfpf: (libc)Rounding Functions.
* ufromfpfN: (libc)Rounding Functions.
* ufromfpfNx: (libc)Rounding Functions.
* ufromfpl: (libc)Rounding Functions.
* ufromfpx: (libc)Rounding Functions.
* ufromfpxf: (libc)Rounding Functions.
* ufromfpxfN: (libc)Rounding Functions.
* ufromfpxfNx: (libc)Rounding Functions.
* ufromfpxl: (libc)Rounding Functions.
* ulimit: (libc)Limits on Resources.
* umask: (libc)Setting Permissions.
* umount2: (libc)Mount-Unmount-Remount.
* umount: (libc)Mount-Unmount-Remount.
* uname: (libc)Platform Type.
* ungetc: (libc)How Unread.
* ungetwc: (libc)How Unread.
* unlink: (libc)Deleting Files.
* unlockpt: (libc)Allocation.
* unsetenv: (libc)Environment Access.
* updwtmp: (libc)Manipulating the Database.
* utime: (libc)File Times.
* utimes: (libc)File Times.
* utmpname: (libc)Manipulating the Database.
* utmpxname: (libc)XPG Functions.
* va_arg: (libc)Argument Macros.
* va_copy: (libc)Argument Macros.
* va_end: (libc)Argument Macros.
* va_start: (libc)Argument Macros.
* valloc: (libc)Aligned Memory Blocks.
* vasprintf: (libc)Variable Arguments Output.
* verr: (libc)Error Messages.
* verrx: (libc)Error Messages.
* versionsort64: (libc)Scanning Directory Content.
* versionsort: (libc)Scanning Directory Content.
* vfork: (libc)Creating a Process.
* vfprintf: (libc)Variable Arguments Output.
* vfscanf: (libc)Variable Arguments Input.
* vfwprintf: (libc)Variable Arguments Output.
* vfwscanf: (libc)Variable Arguments Input.
* vlimit: (libc)Limits on Resources.
* vprintf: (libc)Variable Arguments Output.
* vscanf: (libc)Variable Arguments Input.
* vsnprintf: (libc)Variable Arguments Output.
* vsprintf: (libc)Variable Arguments Output.
* vsscanf: (libc)Variable Arguments Input.
* vswprintf: (libc)Variable Arguments Output.
* vswscanf: (libc)Variable Arguments Input.
* vsyslog: (libc)syslog; vsyslog.
* vwarn: (libc)Error Messages.
* vwarnx: (libc)Error Messages.
* vwprintf: (libc)Variable Arguments Output.
* vwscanf: (libc)Variable Arguments Input.
* wait3: (libc)BSD Wait Functions.
* wait4: (libc)Process Completion.
* wait: (libc)Process Completion.
* waitpid: (libc)Process Completion.
* warn: (libc)Error Messages.
* warnx: (libc)Error Messages.
* wcpcpy: (libc)Copying Strings and Arrays.
* wcpncpy: (libc)Truncating Strings.
* wcrtomb: (libc)Converting a Character.
* wcscasecmp: (libc)String/Array Comparison.
* wcscat: (libc)Concatenating Strings.
* wcschr: (libc)Search Functions.
* wcschrnul: (libc)Search Functions.
* wcscmp: (libc)String/Array Comparison.
* wcscoll: (libc)Collation Functions.
* wcscpy: (libc)Copying Strings and Arrays.
* wcscspn: (libc)Search Functions.
* wcsdup: (libc)Copying Strings and Arrays.
* wcsftime: (libc)Formatting Calendar Time.
* wcslen: (libc)String Length.
* wcsncasecmp: (libc)String/Array Comparison.
* wcsncat: (libc)Truncating Strings.
* wcsncmp: (libc)String/Array Comparison.
* wcsncpy: (libc)Truncating Strings.
* wcsnlen: (libc)String Length.
* wcsnrtombs: (libc)Converting Strings.
* wcspbrk: (libc)Search Functions.
* wcsrchr: (libc)Search Functions.
* wcsrtombs: (libc)Converting Strings.
* wcsspn: (libc)Search Functions.
* wcsstr: (libc)Search Functions.
* wcstod: (libc)Parsing of Floats.
* wcstof: (libc)Parsing of Floats.
* wcstofN: (libc)Parsing of Floats.
* wcstofNx: (libc)Parsing of Floats.
* wcstoimax: (libc)Parsing of Integers.
* wcstok: (libc)Finding Tokens in a String.
* wcstol: (libc)Parsing of Integers.
* wcstold: (libc)Parsing of Floats.
* wcstoll: (libc)Parsing of Integers.
* wcstombs: (libc)Non-reentrant String Conversion.
* wcstoq: (libc)Parsing of Integers.
* wcstoul: (libc)Parsing of Integers.
* wcstoull: (libc)Parsing of Integers.
* wcstoumax: (libc)Parsing of Integers.
* wcstouq: (libc)Parsing of Integers.
* wcswcs: (libc)Search Functions.
* wcsxfrm: (libc)Collation Functions.
* wctob: (libc)Converting a Character.
* wctomb: (libc)Non-reentrant Character Conversion.
* wctrans: (libc)Wide Character Case Conversion.
* wctype: (libc)Classification of Wide Characters.
* wmemchr: (libc)Search Functions.
* wmemcmp: (libc)String/Array Comparison.
* wmemcpy: (libc)Copying Strings and Arrays.
* wmemmove: (libc)Copying Strings and Arrays.
* wmempcpy: (libc)Copying Strings and Arrays.
* wmemset: (libc)Copying Strings and Arrays.
* wordexp: (libc)Calling Wordexp.
* wordfree: (libc)Calling Wordexp.
* wprintf: (libc)Formatted Output Functions.
* write: (libc)I/O Primitives.
* writev: (libc)Scatter-Gather.
* wscanf: (libc)Formatted Input Functions.
* y0: (libc)Special Functions.
* y0f: (libc)Special Functions.
* y0fN: (libc)Special Functions.
* y0fNx: (libc)Special Functions.
* y0l: (libc)Special Functions.
* y1: (libc)Special Functions.
* y1f: (libc)Special Functions.
* y1fN: (libc)Special Functions.
* y1fNx: (libc)Special Functions.
* y1l: (libc)Special Functions.
* yn: (libc)Special Functions.
* ynf: (libc)Special Functions.
* ynfN: (libc)Special Functions.
* ynfNx: (libc)Special Functions.
* ynl: (libc)Special Functions.
END-INFO-DIR-ENTRY


File: libc.info,  Node: Installation,  Next: Maintenance,  Prev: Library Summary,  Up: Top

Appendix C Installing the GNU C Library
***************************************

Before you do anything else, you should read the FAQ at
<https://sourceware.org/glibc/wiki/FAQ>.  It answers common questions
and describes problems you may experience with compilation and
installation.

   You will need recent versions of several GNU tools: definitely GCC
and GNU Make, and possibly others.  *Note Tools for Compilation::,
below.

* Menu:

* Configuring and compiling::   How to compile and test GNU libc.
* Running make install::        How to install it once you’ve got it
 compiled.
* Tools for Compilation::       You’ll need these first.
* Linux::                       Specific advice for GNU/Linux systems.
* Reporting Bugs::              So they’ll get fixed.


File: libc.info,  Node: Configuring and compiling,  Next: Running make install,  Up: Installation

C.1 Configuring and compiling the GNU C Library
===============================================

The GNU C Library cannot be compiled in the source directory.  You must
build it in a separate build directory.  For example, if you have
unpacked the GNU C Library sources in ‘/src/gnu/glibc-VERSION’, create a
directory ‘/src/gnu/glibc-build’ to put the object files in.  This
allows removing the whole build directory in case an error occurs, which
is the safest way to get a fresh start and should always be done.

   From your object directory, run the shell script ‘configure’ located
at the top level of the source tree.  In the scenario above, you’d type

     $ ../glibc-VERSION/configure ARGS…

   Please note that even though you’re building in a separate build
directory, the compilation may need to create or modify files and
directories in the source directory.

‘configure’ takes many options, but the only one that is usually
mandatory is ‘--prefix’.  This option tells ‘configure’ where you want
the GNU C Library installed.  This defaults to ‘/usr/local’, but the
normal setting to install as the standard system library is
‘--prefix=/usr’ for GNU/Linux systems and ‘--prefix=’ (an empty prefix)
for GNU/Hurd systems.

   It may also be useful to pass ‘CC=COMPILER’ and ‘CFLAGS=FLAGS’
arguments to ‘configure’.  ‘CC’ selects the C compiler that will be
used, and ‘CFLAGS’ sets optimization options for the compiler.  Any
compiler options required for all compilations, such as options
selecting an ABI or a processor for which to generate code, should be
included in ‘CC’.  Options that may be overridden by the GNU C Library
build system for particular files, such as for optimization and
debugging, should go in ‘CFLAGS’.  The default value of ‘CFLAGS’ is ‘-g
-O2’, and the GNU C Library cannot be compiled without optimization, so
if ‘CFLAGS’ is specified it must enable optimization.  For example:

     $ ../glibc-VERSION/configure CC="gcc -m32" CFLAGS="-O3"

   The following list describes all of the available options for
‘configure’:

‘--prefix=DIRECTORY’
     Install machine-independent data files in subdirectories of
     ‘DIRECTORY’.  The default is to install in ‘/usr/local’.

‘--exec-prefix=DIRECTORY’
     Install the library and other machine-dependent files in
     subdirectories of ‘DIRECTORY’.  The default is to the ‘--prefix’
     directory if that option is specified, or ‘/usr/local’ otherwise.

‘--with-headers=DIRECTORY’
     Look for kernel header files in DIRECTORY, not ‘/usr/include’.  The
     GNU C Library needs information from the kernel’s header files
     describing the interface to the kernel.  The GNU C Library will
     normally look in ‘/usr/include’ for them, but if you specify this
     option, it will look in DIRECTORY instead.

     This option is primarily of use on a system where the headers in
     ‘/usr/include’ come from an older version of the GNU C Library.
     Conflicts can occasionally happen in this case.  You can also use
     this option if you want to compile the GNU C Library with a newer
     set of kernel headers than the ones found in ‘/usr/include’.

‘--enable-kernel=VERSION’
     This option is currently only useful on GNU/Linux systems.  The
     VERSION parameter should have the form X.Y.Z and describes the
     smallest version of the Linux kernel the generated library is
     expected to support.  The higher the VERSION number is, the less
     compatibility code is added, and the faster the code gets.

‘--with-binutils=DIRECTORY’
     Use the binutils (assembler and linker) in ‘DIRECTORY’, not the
     ones the C compiler would default to.  You can use this option if
     the default binutils on your system cannot deal with all the
     constructs in the GNU C Library.  In that case, ‘configure’ will
     detect the problem and suppress these constructs, so that the
     library will still be usable, but functionality may be lost—for
     example, you can’t build a shared libc with old binutils.

‘--with-default-link’
     With ‘--with-default-link’, the build system does not use a custom
     linker script for linking shared objects.  The default is
     ‘--without-default-link’, because the custom linker script is
     needed for full RELRO protection.

‘--with-nonshared-cflags=CFLAGS’
     Use additional compiler flags CFLAGS to build the parts of the
     library which are always statically linked into applications and
     libraries even with shared linking (that is, the object files
     contained in ‘lib*_nonshared.a’ libraries).  The build process will
     automatically use the appropriate flags, but this option can be
     used to set additional flags required for building applications and
     libraries, to match local policy.  For example, if such a policy
     requires that all code linked into applications must be built with
     source fortification,
     ‘--with-nonshared-cflags=-Wp,-D_FORTIFY_SOURCE=2’ will make sure
     that the objects in ‘libc_nonshared.a’ are compiled with this flag
     (although this will not affect the generated code in this
     particular case and potentially change debugging information and
     metadata only).

‘--with-rtld-early-cflags=CFLAGS’
     Use additional compiler flags CFLAGS to build the early startup
     code of the dynamic linker.  These flags can be used to enable
     early dynamic linker diagnostics to run on CPUs which are not
     compatible with the rest of the GNU C Library, for example, due to
     compiler flags which target a later instruction set architecture
     (ISA).

‘--with-timeoutfactor=NUM’
     Specify an integer NUM to scale the timeout of test programs.  This
     factor can be changed at run time using ‘TIMEOUTFACTOR’ environment
     variable.

‘--disable-shared’
     Don’t build shared libraries even if it is possible.  Not all
     systems support shared libraries; you need ELF support and
     (currently) the GNU linker.

‘--disable-default-pie’
     Don’t build glibc programs and the testsuite as position
     independent executables (PIE). By default, glibc programs and tests
     are created as position independent executables on targets that
     support it.  If the toolchain and architecture support it, static
     executables are built as static PIE and the resulting glibc can be
     used with the GCC option, -static-pie, which is available with GCC
     8 or above, to create static PIE.

‘--enable-cet’
‘--enable-cet=permissive’
     Enable Intel Control-flow Enforcement Technology (CET) support.
     When the GNU C Library is built with ‘--enable-cet’ or
     ‘--enable-cet=permissive’, the resulting library is protected with
     indirect branch tracking (IBT) and shadow stack (SHSTK).  When CET
     is enabled, the GNU C Library is compatible with all existing
     executables and shared libraries.  This feature is currently
     supported on i386, x86_64 and x32 with GCC 8 and binutils 2.29 or
     later.  Note that when CET is enabled, the GNU C Library requires
     CPUs capable of multi-byte NOPs, like x86-64 processors as well as
     Intel Pentium Pro or newer.  With ‘--enable-cet’, it is an error to
     dlopen a non CET enabled shared library in CET enabled application.
     With ‘--enable-cet=permissive’, CET is disabled when dlopening a
     non CET enabled shared library in CET enabled application.

     NOTE: ‘--enable-cet’ has been tested for i686, x86_64 and x32 on
     non-CET processors.  ‘--enable-cet’ has been tested for i686,
     x86_64 and x32 on CET processors.

‘--enable-memory-tagging’
     Enable memory tagging support if the architecture supports it.
     When the GNU C Library is built with this option then the resulting
     library will be able to control the use of tagged memory when
     hardware support is present by use of the tunable
     ‘glibc.mem.tagging’.  This includes the generation of tagged memory
     when using the ‘malloc’ APIs.

     At present only AArch64 platforms with MTE provide this
     functionality, although the library will still operate (without
     memory tagging) on older versions of the architecture.

     The default is to disable support for memory tagging.

‘--disable-profile’
     Don’t build libraries with profiling information.  You may want to
     use this option if you don’t plan to do profiling.

‘--enable-static-nss’
     Compile static versions of the NSS (Name Service Switch) libraries.
     This is not recommended because it defeats the purpose of NSS; a
     program linked statically with the NSS libraries cannot be
     dynamically reconfigured to use a different name database.

‘--enable-hardcoded-path-in-tests’
     By default, dynamic tests are linked to run with the installed C
     library.  This option hardcodes the newly built C library path in
     dynamic tests so that they can be invoked directly.

‘--disable-timezone-tools’
     By default, timezone related utilities (‘zic’, ‘zdump’, and
     ‘tzselect’) are installed with the GNU C Library.  If you are
     building these independently (e.g.  by using the ‘tzcode’ package),
     then this option will allow disabling the install of these.

     Note that you need to make sure the external tools are kept in sync
     with the versions that the GNU C Library expects as the data
     formats may change over time.  Consult the ‘timezone’ subdirectory
     for more details.

‘--enable-stack-protector’
‘--enable-stack-protector=strong’
‘--enable-stack-protector=all’
     Compile the C library and all other parts of the glibc package
     (including the threading and math libraries, NSS modules, and
     transliteration modules) using the GCC ‘-fstack-protector’,
     ‘-fstack-protector-strong’ or ‘-fstack-protector-all’ options to
     detect stack overruns.  Only the dynamic linker and a small number
     of routines called directly from assembler are excluded from this
     protection.

‘--enable-bind-now’
     Disable lazy binding for installed shared objects and programs.
     This provides additional security hardening because it enables full
     RELRO and a read-only global offset table (GOT), at the cost of
     slightly increased program load times.

‘--enable-pt_chown’
     The file ‘pt_chown’ is a helper binary for ‘grantpt’ (*note
     Pseudo-Terminals: Allocation.) that is installed setuid root to fix
     up pseudo-terminal ownership on GNU/Hurd.  It is not required on
     GNU/Linux, and the GNU C Library will not use the installed
     ‘pt_chown’ program when configured with ‘--enable-pt_chown’.

‘--disable-werror’
     By default, the GNU C Library is built with ‘-Werror’.  If you wish
     to build without this option (for example, if building with a newer
     version of GCC than this version of the GNU C Library was tested
     with, so new warnings cause the build with ‘-Werror’ to fail), you
     can configure with ‘--disable-werror’.

‘--disable-mathvec’
     By default for x86_64, the GNU C Library is built with the vector
     math library.  Use this option to disable the vector math library.

‘--enable-tunables’
     Tunables support allows additional library parameters to be
     customized at runtime.  This feature is enabled by default.  This
     option can take the following values:

     ‘yes’
          This is the default if no option is passed to configure.  This
          enables tunables and selects the default frontend (currently
          ‘valstring’).

     ‘no’
          This option disables tunables.

     ‘valstring’
          This enables tunables and selects the ‘valstring’ frontend for
          tunables.  This frontend allows users to specify tunables as a
          colon-separated list in a single environment variable
          ‘GLIBC_TUNABLES’.

‘--disable-crypt’
     Do not install the passphrase-hashing library ‘libcrypt’ or the
     header file ‘crypt.h’.  ‘unistd.h’ will still declare the function
     ‘crypt’.  Using this option does not change the set of programs
     that may need to be linked with ‘-lcrypt’; it only means that the
     GNU C Library will not provide that library.

     This option is for hackers and distributions experimenting with
     independently-maintained implementations of libcrypt.  It may
     become the default in a future release.

‘--disable-experimental-malloc’
     By default, a per-thread cache is enabled in ‘malloc’.  While this
     cache can be disabled on a per-application basis using tunables
     (set glibc.malloc.tcache_count to zero), this option can be used to
     remove it from the build completely.

‘--disable-scv’
     Disable using ‘scv’ instruction for syscalls.  All syscalls will
     use ‘sc’ instead, even if the kernel supports ‘scv’.  PowerPC only.

‘--build=BUILD-SYSTEM’
‘--host=HOST-SYSTEM’
     These options are for cross-compiling.  If you specify both options
     and BUILD-SYSTEM is different from HOST-SYSTEM, ‘configure’ will
     prepare to cross-compile the GNU C Library from BUILD-SYSTEM to be
     used on HOST-SYSTEM.  You’ll probably need the ‘--with-headers’
     option too, and you may have to override CONFIGURE’s selection of
     the compiler and/or binutils.

     If you only specify ‘--host’, ‘configure’ will prepare for a native
     compile but use what you specify instead of guessing what your
     system is.  This is most useful to change the CPU submodel.  For
     example, if ‘configure’ guesses your machine as ‘i686-pc-linux-gnu’
     but you want to compile a library for 586es, give
     ‘--host=i586-pc-linux-gnu’ or just ‘--host=i586-linux’ and add the
     appropriate compiler flags (‘-mcpu=i586’ will do the trick) to
     ‘CC’.

     If you specify just ‘--build’, ‘configure’ will get confused.

‘--with-pkgversion=VERSION’
     Specify a description, possibly including a build number or build
     date, of the binaries being built, to be included in ‘--version’
     output from programs installed with the GNU C Library.  For
     example, ‘--with-pkgversion='FooBar GNU/Linux glibc build 123'’.
     The default value is ‘GNU libc’.

‘--with-bugurl=URL’
     Specify the URL that users should visit if they wish to report a
     bug, to be included in ‘--help’ output from programs installed with
     the GNU C Library.  The default value refers to the main
     bug-reporting information for the GNU C Library.

   To build the library and related programs, type ‘make’.  This will
produce a lot of output, some of which may look like errors from ‘make’
but aren’t.  Look for error messages from ‘make’ containing ‘***’.
Those indicate that something is seriously wrong.

   The compilation process can take a long time, depending on the
configuration and the speed of your machine.  Some complex modules may
take a very long time to compile, as much as several minutes on slower
machines.  Do not panic if the compiler appears to hang.

   If you want to run a parallel make, simply pass the ‘-j’ option with
an appropriate numeric parameter to ‘make’.  You need a recent GNU
‘make’ version, though.

   To build and run test programs which exercise some of the library
facilities, type ‘make check’.  If it does not complete successfully, do
not use the built library, and report a bug after verifying that the
problem is not already known.  *Note Reporting Bugs::, for instructions
on reporting bugs.  Note that some of the tests assume they are not
being run by ‘root’.  We recommend you compile and test the GNU C
Library as an unprivileged user.

   Before reporting bugs make sure there is no problem with your system.
The tests (and later installation) use some pre-existing files of the
system such as ‘/etc/passwd’, ‘/etc/nsswitch.conf’ and others.  These
files must all contain correct and sensible content.

   Normally, ‘make check’ will run all the tests before reporting all
problems found and exiting with error status if any problems occurred.
You can specify ‘stop-on-test-failure=y’ when running ‘make check’ to
make the test run stop and exit with an error status immediately when a
failure occurs.

   To format the ‘GNU C Library Reference Manual’ for printing, type
‘make dvi’.  You need a working TeX installation to do this.  The
distribution builds the on-line formatted version of the manual, as Info
files, as part of the build process.  You can build them manually with
‘make info’.

   The library has a number of special-purpose configuration parameters
which you can find in ‘Makeconfig’.  These can be overwritten with the
file ‘configparms’.  To change them, create a ‘configparms’ in your
build directory and add values as appropriate for your system.  The file
is included and parsed by ‘make’ and has to follow the conventions for
makefiles.

   It is easy to configure the GNU C Library for cross-compilation by
setting a few variables in ‘configparms’.  Set ‘CC’ to the
cross-compiler for the target you configured the library for; it is
important to use this same ‘CC’ value when running ‘configure’, like
this: ‘configure TARGET CC=TARGET-gcc’.  Set ‘BUILD_CC’ to the compiler
to use for programs run on the build system as part of compiling the
library.  You may need to set ‘AR’ to cross-compiling versions of ‘ar’
if the native tools are not configured to work with object files for the
target you configured for.  When cross-compiling the GNU C Library, it
may be tested using ‘make check
test-wrapper="SRCDIR/scripts/cross-test-ssh.sh HOSTNAME"’, where SRCDIR
is the absolute directory name for the main source directory and
HOSTNAME is the host name of a system that can run the newly built
binaries of the GNU C Library.  The source and build directories must be
visible at the same locations on both the build system and HOSTNAME.
The ‘cross-test-ssh.sh’ script requires ‘flock’ from ‘util-linux’ to
work when GLIBC_TEST_ALLOW_TIME_SETTING environment variable is set.

   It is also possible to execute tests, which require setting the date
on the target machine.  Following use cases are supported:
   • ‘GLIBC_TEST_ALLOW_TIME_SETTING’ is set in the environment in which
     eligible tests are executed and have the privilege to run
     ‘clock_settime’.  In this case, nothing prevents those tests from
     running in parallel, so the caller shall assure that those tests
     are serialized or provide a proper wrapper script for them.

   • The ‘cross-test-ssh.sh’ script is used and one passes the
     ‘--allow-time-setting’ flag.  In this case, both sets
     ‘GLIBC_TEST_ALLOW_TIME_SETTING’ and serialization of test execution
     are assured automatically.

   In general, when testing the GNU C Library, ‘test-wrapper’ may be set
to the name and arguments of any program to run newly built binaries.
This program must preserve the arguments to the binary being run, its
working directory and the standard input, output and error file
descriptors.  If ‘TEST-WRAPPER env’ will not work to run a program with
environment variables set, then ‘test-wrapper-env’ must be set to a
program that runs a newly built program with environment variable
assignments in effect, those assignments being specified as ‘VAR=VALUE’
before the name of the program to be run.  If multiple assignments to
the same variable are specified, the last assignment specified must take
precedence.  Similarly, if ‘TEST-WRAPPER env -i’ will not work to run a
program with an environment completely empty of variables except those
directly assigned, then ‘test-wrapper-env-only’ must be set; its use has
the same syntax as ‘test-wrapper-env’, the only difference in its
semantics being starting with an empty set of environment variables
rather than the ambient set.

   For AArch64 with SVE, when testing the GNU C Library, ‘test-wrapper’
may be set to "SRCDIR/sysdeps/unix/sysv/linux/aarch64/vltest.py
VECTOR-LENGTH" to change Vector Length.


File: libc.info,  Node: Running make install,  Next: Tools for Compilation,  Prev: Configuring and compiling,  Up: Installation

C.2 Installing the C Library
============================

To install the library and its header files, and the Info files of the
manual, type ‘make install’.  This will build things, if necessary,
before installing them; however, you should still compile everything
first.  If you are installing the GNU C Library as your primary C
library, we recommend that you shut the system down to single-user mode
first, and reboot afterward.  This minimizes the risk of breaking things
when the library changes out from underneath.

   ‘make install’ will do the entire job of upgrading from a previous
installation of the GNU C Library version 2.x.  There may sometimes be
headers left behind from the previous installation, but those are
generally harmless.  If you want to avoid leaving headers behind you can
do things in the following order.

   You must first build the library (‘make’), optionally check it (‘make
check’), switch the include directories and then install (‘make
install’).  The steps must be done in this order.  Not moving the
directory before install will result in an unusable mixture of header
files from both libraries, but configuring, building, and checking the
library requires the ability to compile and run programs against the old
library.  The new ‘/usr/include’, after switching the include
directories and before installing the library should contain the Linux
headers, but nothing else.  If you do this, you will need to restore any
headers from libraries other than the GNU C Library yourself after
installing the library.

   You can install the GNU C Library somewhere other than where you
configured it to go by setting the ‘DESTDIR’ GNU standard make variable
on the command line for ‘make install’.  The value of this variable is
prepended to all the paths for installation.  This is useful when
setting up a chroot environment or preparing a binary distribution.  The
directory should be specified with an absolute file name.  Installing
with the ‘prefix’ and ‘exec_prefix’ GNU standard make variables set is
not supported.

   The GNU C Library includes a daemon called ‘nscd’, which you may or
may not want to run.  ‘nscd’ caches name service lookups; it can
dramatically improve performance with NIS+, and may help with DNS as
well.

   One auxiliary program, ‘/usr/libexec/pt_chown’, is installed setuid
‘root’ if the ‘--enable-pt_chown’ configuration option is used.  This
program is invoked by the ‘grantpt’ function; it sets the permissions on
a pseudoterminal so it can be used by the calling process.  If you are
using a Linux kernel with the ‘devpts’ filesystem enabled and mounted at
‘/dev/pts’, you don’t need this program.

   After installation you should configure the timezone and install
locales for your system.  The time zone configuration ensures that your
system time matches the time for your current timezone.  The locales
ensure that the display of information on your system matches the
expectations of your language and geographic region.

   The GNU C Library is able to use two kinds of localization
information sources, the first is a locale database named
‘locale-archive’ which is generally installed as
‘/usr/lib/locale/locale-archive’.  The locale archive has the benefit of
taking up less space and being very fast to load, but only if you plan
to install sixty or more locales.  If you plan to install one or two
locales you can instead install individual locales into their self-named
directories e.g. ‘/usr/lib/locale/en_US.utf8’.  For example to install
the German locale using the character set for UTF-8 with name ‘de_DE’
into the locale archive issue the command ‘localedef -i de_DE -f UTF-8
de_DE’, and to install just the one locale issue the command ‘localedef
--no-archive -i de_DE -f UTF-8 de_DE’.  To configure all locales that
are supported by the GNU C Library, you can issue from your build
directory the command ‘make localedata/install-locales’ to install all
locales into the locale archive or ‘make
localedata/install-locale-files’ to install all locales as files in the
default configured locale installation directory (derived from
‘--prefix’ or ‘--localedir’).  To install into an alternative system
root use ‘DESTDIR’ e.g. ‘make localedata/install-locale-files
DESTDIR=/opt/glibc’, but note that this does not change the configured
prefix.

   To configure the locally used timezone, set the ‘TZ’ environment
variable.  The script ‘tzselect’ helps you to select the right value.
As an example, for Germany, ‘tzselect’ would tell you to use
‘TZ='Europe/Berlin'’.  For a system wide installation (the given paths
are for an installation with ‘--prefix=/usr’), link the timezone file
which is in ‘/usr/share/zoneinfo’ to the file ‘/etc/localtime’.  For
Germany, you might execute ‘ln -s /usr/share/zoneinfo/Europe/Berlin
/etc/localtime’.


File: libc.info,  Node: Tools for Compilation,  Next: Linux,  Prev: Running make install,  Up: Installation

C.3 Recommended Tools for Compilation
=====================================

We recommend installing the following GNU tools before attempting to
build the GNU C Library:

   • GNU ‘make’ 4.0 or newer

     As of relase time, GNU ‘make’ 4.3 is the newest verified to work to
     build the GNU C Library.

   • GCC 6.2 or newer

     GCC 6.2 or higher is required.  In general it is recommended to use
     the newest version of the compiler that is known to work for
     building the GNU C Library, as newer compilers usually produce
     better code.  As of release time, GCC 12.1 is the newest compiler
     verified to work to build the GNU C Library.

     For PowerPC 64-bits little-endian (powerpc64le), a GCC version with
     support for ‘-mno-gnu-attribute’, ‘-mabi=ieeelongdouble’, and
     ‘-mabi=ibmlondouble’ is required.  Likewise, the compiler must also
     support passing ‘-mlong-double-128’ with the preceding options.  As
     of release, this implies GCC 7.4 and newer (excepting GCC 7.5.0,
     see GCC PR94200).  These additional features are required for
     building the GNU C Library with support for IEEE long double.

     For ARC architecture builds, GCC 8.3 or higher is needed.

     For s390x architecture builds, GCC 7.1 or higher is needed (See gcc
     Bug 98269).

     For multi-arch support it is recommended to use a GCC which has
     been built with support for GNU indirect functions.  This ensures
     that correct debugging information is generated for functions
     selected by IFUNC resolvers.  This support can either be enabled by
     configuring GCC with ‘--enable-gnu-indirect-function’, or by
     enabling it by default by setting ‘default_gnu_indirect_function’
     variable for a particular architecture in the GCC source file
     ‘gcc/config.gcc’.

     You can use whatever compiler you like to compile programs that use
     the GNU C Library.

     Check the FAQ for any special compiler issues on particular
     platforms.

   • GNU ‘binutils’ 2.25 or later

     You must use GNU ‘binutils’ (as and ld) to build the GNU C Library.
     No other assembler or linker has the necessary functionality at the
     moment.  As of release time, GNU ‘binutils’ 2.38 is the newest
     verified to work to build the GNU C Library.

     For PowerPC 64-bits little-endian (powerpc64le), ‘objcopy’ is
     required to support ‘--update-section’.  This option requires
     binutils 2.26 or newer.

     ARC architecture needs ‘binutils’ 2.32 or higher for TLS related
     fixes.

   • GNU ‘texinfo’ 4.7 or later

     To correctly translate and install the Texinfo documentation you
     need this version of the ‘texinfo’ package.  Earlier versions do
     not understand all the tags used in the document, and the
     installation mechanism for the info files is not present or works
     differently.  As of release time, ‘texinfo’ 6.8 is the newest
     verified to work to build the GNU C Library.

   • GNU ‘awk’ 3.1.2, or higher

     ‘awk’ is used in several places to generate files.  Some ‘gawk’
     extensions are used, including the ‘asorti’ function, which was
     introduced in version 3.1.2 of ‘gawk’.  As of release time, ‘gawk’
     version 5.1.1 is the newest verified to work to build the GNU C
     Library.

   • GNU ‘bison’ 2.7 or later

     ‘bison’ is used to generate the ‘yacc’ parser code in the ‘intl’
     subdirectory.  As of release time, ‘bison’ version 3.8.2 is the
     newest verified to work to build the GNU C Library.

   • Perl 5

     Perl is not required, but if present it is used in some tests and
     the ‘mtrace’ program, to build the GNU C Library manual.  As of
     release time ‘perl’ version 5.34.1 is the newest verified to work
     to build the GNU C Library.

   • GNU ‘sed’ 3.02 or newer

     ‘Sed’ is used in several places to generate files.  Most scripts
     work with any version of ‘sed’.  As of release time, ‘sed’ version
     4.8 is the newest verified to work to build the GNU C Library.

   • Python 3.4 or later

     Python is required to build the GNU C Library.  As of release time,
     Python 3.10.5 is the newest verified to work for building and
     testing the GNU C Library.

   • PExpect 4.0

     The pretty printer tests drive GDB through test programs and
     compare its output to the printers’.  PExpect is used to capture
     the output of GDB, and should be compatible with the Python version
     in your system.  As of release time PExpect 4.8.0 is the newest
     verified to work to test the pretty printers.

   • GDB 7.8 or later with support for Python 2.7/3.4 or later

     GDB itself needs to be configured with Python support in order to
     use the pretty printers.  Notice that your system having Python
     available doesn’t imply that GDB supports it, nor that your
     system’s Python and GDB’s have the same version.  As of release
     time GNU ‘debugger’ 12.1 is the newest verified to work to test the
     pretty printers.

     Unless Python, PExpect and GDB with Python support are present, the
     printer tests will report themselves as ‘UNSUPPORTED’.  Notice that
     some of the printer tests require the GNU C Library to be compiled
     with debugging symbols.

If you change any of the ‘configure.ac’ files you will also need

   • GNU ‘autoconf’ 2.69 (exactly)

and if you change any of the message translation files you will need

   • GNU ‘gettext’ 0.10.36 or later

     As of release time, GNU ‘gettext’ version 0.21 is the newest
     version verified to work to build the GNU C Library.

You may also need these packages if you upgrade your source tree using
patches, although we try to avoid this.


File: libc.info,  Node: Linux,  Next: Reporting Bugs,  Prev: Tools for Compilation,  Up: Installation

C.4 Specific advice for GNU/Linux systems
=========================================

If you are installing the GNU C Library on GNU/Linux systems, you need
to have the header files from a 3.2 or newer kernel around for
reference.  (For the ia64 architecture, you need version 3.2.18 or newer
because this is the first version with support for the ‘accept4’ system
call.)  These headers must be installed using ‘make headers_install’;
the headers present in the kernel source directory are not suitable for
direct use by the GNU C Library.  You do not need to use that kernel,
just have its headers installed where the GNU C Library can access them,
referred to here as INSTALL-DIRECTORY.  The easiest way to do this is to
unpack it in a directory such as ‘/usr/src/linux-VERSION’.  In that
directory, run ‘make headers_install
INSTALL_HDR_PATH=INSTALL-DIRECTORY’.  Finally, configure the GNU C
Library with the option ‘--with-headers=INSTALL-DIRECTORY/include’.  Use
the most recent kernel you can get your hands on.  (If you are
cross-compiling the GNU C Library, you need to specify
‘ARCH=ARCHITECTURE’ in the ‘make headers_install’ command, where
ARCHITECTURE is the architecture name used by the Linux kernel, such as
‘x86’ or ‘powerpc’.)

   After installing the GNU C Library, you may need to remove or rename
directories such as ‘/usr/include/linux’ and ‘/usr/include/asm’, and
replace them with copies of directories such as ‘linux’ and ‘asm’ from
‘INSTALL-DIRECTORY/include’.  All directories present in
‘INSTALL-DIRECTORY/include’ should be copied, except that the GNU C
Library provides its own version of ‘/usr/include/scsi’; the files
provided by the kernel should be copied without replacing those provided
by the GNU C Library.  The ‘linux’, ‘asm’ and ‘asm-generic’ directories
are required to compile programs using the GNU C Library; the other
directories describe interfaces to the kernel but are not required if
not compiling programs using those interfaces.  You do not need to copy
kernel headers if you did not specify an alternate kernel header source
using ‘--with-headers’.

   The Filesystem Hierarchy Standard for GNU/Linux systems expects some
components of the GNU C Library installation to be in ‘/lib’ and some in
‘/usr/lib’.  This is handled automatically if you configure the GNU C
Library with ‘--prefix=/usr’.  If you set some other prefix or allow it
to default to ‘/usr/local’, then all the components are installed there.

   As of release time, Linux version 5.18 is the newest stable version
verified to work to build the GNU C Library.


File: libc.info,  Node: Reporting Bugs,  Prev: Linux,  Up: Installation

C.5 Reporting Bugs
==================

There are probably bugs in the GNU C Library.  There are certainly
errors and omissions in this manual.  If you report them, they will get
fixed.  If you don’t, no one will ever know about them and they will
remain unfixed for all eternity, if not longer.

   It is a good idea to verify that the problem has not already been
reported.  Bugs are documented in two places: The file ‘BUGS’ describes
a number of well known bugs and the central GNU C Library bug tracking
system has a WWW interface at <https://sourceware.org/bugzilla/>.  The
WWW interface gives you access to open and closed reports.  A closed
report normally includes a patch or a hint on solving the problem.

   To report a bug, first you must find it.  With any luck, this will be
the hard part.  Once you’ve found a bug, make sure it’s really a bug.  A
good way to do this is to see if the GNU C Library behaves the same way
some other C library does.  If so, probably you are wrong and the
libraries are right (but not necessarily).  If not, one of the libraries
is probably wrong.  It might not be the GNU C Library.  Many historical
Unix C libraries permit things that we don’t, such as closing a file
twice.

   If you think you have found some way in which the GNU C Library does
not conform to the ISO and POSIX standards (*note Standards and
Portability::), that is definitely a bug.  Report it!

   Once you’re sure you’ve found a bug, try to narrow it down to the
smallest test case that reproduces the problem.  In the case of a C
library, you really only need to narrow it down to one library function
call, if possible.  This should not be too difficult.

   The final step when you have a simple test case is to report the bug.
Do this at <https://bugs.linaro.org/>.

   If you are not sure how a function should behave, and this manual
doesn’t tell you, that’s a bug in the manual.  Report that too!  If the
function’s behavior disagrees with the manual, then either the library
or the manual has a bug, so report the disagreement.  If you find any
errors or omissions in this manual, please report them to the bug
database.  If you refer to specific sections of the manual, please
include the section names for easier identification.


File: libc.info,  Node: Maintenance,  Next: Platform,  Prev: Installation,  Up: Top

Appendix D Library Maintenance
******************************

* Menu:

* Source Layout::         How to add new functions or header files
                             to the GNU C Library.
* Symbol handling::       How to handle symbols in the GNU C Library.
* Porting::               How to port the GNU C Library to
                             a new machine or operating system.


File: libc.info,  Node: Source Layout,  Next: Symbol handling,  Up: Maintenance

D.1 Adding New Functions
========================

The process of building the library is driven by the makefiles, which
make heavy use of special features of GNU ‘make’.  The makefiles are
very complex, and you probably don’t want to try to understand them.
But what they do is fairly straightforward, and only requires that you
define a few variables in the right places.

   The library sources are divided into subdirectories, grouped by
topic.

   The ‘string’ subdirectory has all the string-manipulation functions,
‘math’ has all the mathematical functions, etc.

   Each subdirectory contains a simple makefile, called ‘Makefile’,
which defines a few ‘make’ variables and then includes the global
makefile ‘Rules’ with a line like:

     include ../Rules

The basic variables that a subdirectory makefile defines are:

‘subdir’
     The name of the subdirectory, for example ‘stdio’.  This variable
     *must* be defined.

‘headers’
     The names of the header files in this section of the library, such
     as ‘stdio.h’.

‘routines’
‘aux’
     The names of the modules (source files) in this section of the
     library.  These should be simple names, such as ‘strlen’ (rather
     than complete file names, such as ‘strlen.c’).  Use ‘routines’ for
     modules that define functions in the library, and ‘aux’ for
     auxiliary modules containing things like data definitions.  But the
     values of ‘routines’ and ‘aux’ are just concatenated, so there
     really is no practical difference.

‘tests’
     The names of test programs for this section of the library.  These
     should be simple names, such as ‘tester’ (rather than complete file
     names, such as ‘tester.c’).  ‘make tests’ will build and run all
     the test programs.  If a test program needs input, put the test
     data in a file called ‘TEST-PROGRAM.input’; it will be given to the
     test program on its standard input.  If a test program wants to be
     run with arguments, put the arguments (all on a single line) in a
     file called ‘TEST-PROGRAM.args’.  Test programs should exit with
     zero status when the test passes, and nonzero status when the test
     indicates a bug in the library or error in building.

‘others’
     The names of “other” programs associated with this section of the
     library.  These are programs which are not tests per se, but are
     other small programs included with the library.  They are built by
     ‘make others’.

‘install-lib’
‘install-data’
‘install’
     Files to be installed by ‘make install’.  Files listed in
     ‘install-lib’ are installed in the directory specified by ‘libdir’
     in ‘configparms’ or ‘Makeconfig’ (*note Installation::).  Files
     listed in ‘install-data’ are installed in the directory specified
     by ‘datadir’ in ‘configparms’ or ‘Makeconfig’.  Files listed in
     ‘install’ are installed in the directory specified by ‘bindir’ in
     ‘configparms’ or ‘Makeconfig’.

‘distribute’
     Other files from this subdirectory which should be put into a
     distribution tar file.  You need not list here the makefile itself
     or the source and header files listed in the other standard
     variables.  Only define ‘distribute’ if there are files used in an
     unusual way that should go into the distribution.

‘generated’
     Files which are generated by ‘Makefile’ in this subdirectory.
     These files will be removed by ‘make clean’, and they will never go
     into a distribution.

‘extra-objs’
     Extra object files which are built by ‘Makefile’ in this
     subdirectory.  This should be a list of file names like ‘foo.o’;
     the files will actually be found in whatever directory object files
     are being built in.  These files will be removed by ‘make clean’.
     This variable is used for secondary object files needed to build
     ‘others’ or ‘tests’.

* Menu:

* Platform: Adding Platform-specific.             Adding platform-specific
                                         features.


File: libc.info,  Node: Adding Platform-specific,  Up: Source Layout

D.1.1 Platform-specific types, macros and functions
---------------------------------------------------

It’s sometimes necessary to provide nonstandard, platform-specific
features to developers.  The C library is traditionally the lowest
library layer, so it makes sense for it to provide these low-level
features.  However, including these features in the C library may be a
disadvantage if another package provides them as well as there will be
two conflicting versions of them.  Also, the features won’t be available
to projects that do not use the GNU C Library but use other GNU tools,
like GCC.

   The current guidelines are:
   • If the header file provides features that only make sense on a
     particular machine architecture and have nothing to do with an
     operating system, then the features should ultimately be provided
     as GCC built-in functions.  Until then, the GNU C Library may
     provide them in the header file.  When the GCC built-in functions
     become available, those provided in the header file should be made
     conditionally available prior to the GCC version in which the
     built-in function was made available.

   • If the header file provides features that are specific to an
     operating system, both GCC and the GNU C Library could provide it,
     but the GNU C Library is preferred as it already has a lot of
     information about the operating system.

   • If the header file provides features that are specific to an
     operating system but used by the GNU C Library, then the GNU C
     Library should provide them.

   The general solution for providing low-level features is to export
them as follows:

   • A nonstandard, low-level header file that defines macros and inline
     functions should be called ‘sys/platform/NAME.h’.

   • Each header file’s name should include the platform name, to avoid
     users thinking there is anything in common between the different
     header files for different platforms.  For example, a
     ‘sys/platform/ARCH.h’ name such as ‘sys/platform/ppc.h’ is better
     than ‘sys/platform.h’.

   • A platform-specific header file provided by the GNU C Library
     should coordinate with GCC such that compiler built-in versions of
     the functions and macros are preferred if available.  This means
     that user programs will only ever need to include
     ‘sys/platform/ARCH.h’, keeping the same names of types, macros, and
     functions for convenience and portability.

   • Each included symbol must have the prefix ‘__ARCH_’, such as
     ‘__ppc_get_timebase’.

   The easiest way to provide a header file is to add it to the
‘sysdep_headers’ variable.  For example, the combination of
Linux-specific header files on PowerPC could be provided like this:

     sysdep_headers += sys/platform/ppc.h

   Then ensure that you have added a ‘sys/platform/ppc.h’ header file in
the machine-specific directory, e.g.,
‘sysdeps/powerpc/sys/platform/ppc.h’.


File: libc.info,  Node: Symbol handling,  Next: Porting,  Prev: Source Layout,  Up: Maintenance

D.2 Symbol handling in the GNU C Library
========================================

* Menu:

* 64-bit time symbol handling :: How to handle 64-bit time related
                                    symbols in the GNU C Library.


File: libc.info,  Node: 64-bit time symbol handling,  Up: Symbol handling

D.2.1 64-bit time symbol handling in the GNU C Library
------------------------------------------------------

With respect to time handling, GNU C Library configurations fall in two
classes depending on the value of ‘__TIMESIZE’:

‘__TIMESIZE == 32’

     These "dual-time" configurations have both 32-bit and 64-bit time
     support.  32-bit time support provides type ‘time_t’ and cannot
     handle dates beyond "Y2038".  64-bit time support provides type
     ‘__time64_t’ and can handle dates beyond "Y2038".

     In these configurations, time-related types have two declarations,
     a 64-bit one, and a 32-bit one; and time-related functions
     generally have two definitions: a 64-bit one, and a 32-bit one
     which is a wrapper around the former.  Therefore, for every
     ‘time_t’-related symbol, there is a corresponding
     ‘__time64_t’-related symbol, the name of which is usually the
     32-bit symbol’s name with ‘__’ (a double underscore) prepended and
     ‘64’ appended.  For instance, the 64-bit-time counterpart of
     ‘clock_gettime’ is ‘__clock_gettime64’.

‘__TIMESIZE == 64’

     These "single-time" configurations only have a 64-bit ‘time_t’ and
     related functions, which can handle dates beyond 2038-01-19
     03:14:07 (aka "Y2038").

     In these configurations, time-related types only have a 64-bit
     declaration; and time-related functions only have one 64-bit
     definition.  However, for every ‘time_t’-related symbol, there is a
     corresponding ‘__time64_t’-related macro, the name of which is
     derived as in the dual-time configuration case, and which expands
     to the symbol’s name.  For instance, the macro ‘__clock_gettime64’
     expands to ‘clock_gettime’.

     These macros are purely internal to the GNU C Library and exist
     only so that a single definition of the 64-bit time functions can
     be used on both single-time and dual-time configurations, and so
     that glibc code can freely call the 64-bit functions internally in
     all configurations.

   Note: at this point, 64-bit time support in dual-time configurations
is work-in-progress, so for these configurations, the public API only
makes the 32-bit time support available.  In a later change, the public
API will allow user code to choose the time size for a given compilation
unit.

   64-bit variants of time-related types or functions are defined for
all configurations and use 64-bit-time symbol names (for dual-time
configurations) or macros (for single-time configurations).

   32-bit variants of time-related types or functions are defined only
for dual-time configurations.

   Here is an example with ‘localtime’:

   Function ‘localtime’ is declared in ‘time/time.h’ as
     extern struct tm *localtime (const time_t *__timer) __THROW;
     libc_hidden_proto (localtime)

   For single-time configurations, ‘__localtime64’ is a macro which
evaluates to ‘localtime’; for dual-time configurations, ‘__localtime64’
is a function similar to ‘localtime’ except it uses Y2038-proof types:
     #if __TIMESIZE == 64
     # define __localtime64 localtime
     #else
     extern struct tm *__localtime64 (const __time64_t *__timer) __THROW;
     libc_hidden_proto (__localtime64)
     #endif

   (note: type ‘time_t’ is replaced with ‘__time64_t’ because ‘time_t’
is not Y2038-proof, but ‘struct tm’ is not replaced because it is
already Y2038-proof.)

   The 64-bit-time implementation of ‘localtime’ is written as follows
and is compiled for both dual-time and single-time configuration
classes.

     struct tm *
     __localtime64 (const __time64_t *t)
     {
       return __tz_convert (*t, 1, &_tmbuf);
     }
     libc_hidden_def (__localtime64)

   The 32-bit-time implementation is a wrapper and is only compiled for
dual-time configurations:

     #if __TIMESIZE != 64

     struct tm *
     localtime (const time_t *t)
     {
       __time64_t t64 = *t;
       return __localtime64 (&t64);
     }
     libc_hidden_def (localtime)

     #endif


File: libc.info,  Node: Porting,  Prev: Symbol handling,  Up: Maintenance

D.3 Porting the GNU C Library
=============================

The GNU C Library is written to be easily portable to a variety of
machines and operating systems.  Machine- and operating system-dependent
functions are well separated to make it easy to add implementations for
new machines or operating systems.  This section describes the layout of
the library source tree and explains the mechanisms used to select
machine-dependent code to use.

   All the machine-dependent and operating system-dependent files in the
library are in the subdirectory ‘sysdeps’ under the top-level library
source directory.  This directory contains a hierarchy of subdirectories
(*note Hierarchy Conventions::).

   Each subdirectory of ‘sysdeps’ contains source files for a particular
machine or operating system, or for a class of machine or operating
system (for example, systems by a particular vendor, or all machines
that use IEEE 754 floating-point format).  A configuration specifies an
ordered list of these subdirectories.  Each subdirectory implicitly
appends its parent directory to the list.  For example, specifying the
list ‘unix/bsd/vax’ is equivalent to specifying the list ‘unix/bsd/vax
unix/bsd unix’.  A subdirectory can also specify that it implies other
subdirectories which are not directly above it in the directory
hierarchy.  If the file ‘Implies’ exists in a subdirectory, it lists
other subdirectories of ‘sysdeps’ which are appended to the list,
appearing after the subdirectory containing the ‘Implies’ file.  Lines
in an ‘Implies’ file that begin with a ‘#’ character are ignored as
comments.  For example, ‘unix/bsd/Implies’ contains:
     # BSD has Internet-related things.
     unix/inet
and ‘unix/Implies’ contains:
     posix

So the final list is ‘unix/bsd/vax unix/bsd unix/inet unix posix’.

   ‘sysdeps’ has a “special” subdirectory called ‘generic’.  It is
always implicitly appended to the list of subdirectories, so you needn’t
put it in an ‘Implies’ file, and you should not create any
subdirectories under it intended to be new specific categories.
‘generic’ serves two purposes.  First, the makefiles do not bother to
look for a system-dependent version of a file that’s not in ‘generic’.
This means that any system-dependent source file must have an analogue
in ‘generic’, even if the routines defined by that file are not
implemented on other platforms.  Second, the ‘generic’ version of a
system-dependent file is used if the makefiles do not find a version
specific to the system you’re compiling for.

   If it is possible to implement the routines in a ‘generic’ file in
machine-independent C, using only other machine-independent functions in
the C library, then you should do so.  Otherwise, make them stubs.  A
"stub" function is a function which cannot be implemented on a
particular machine or operating system.  Stub functions always return an
error, and set ‘errno’ to ‘ENOSYS’ (Function not implemented).  *Note
Error Reporting::.  If you define a stub function, you must place the
statement ‘stub_warning(FUNCTION)’, where FUNCTION is the name of your
function, after its definition.  This causes the function to be listed
in the installed ‘<gnu/stubs.h>’, and makes GNU ld warn when the
function is used.

   Some rare functions are only useful on specific systems and aren’t
defined at all on others; these do not appear anywhere in the
system-independent source code or makefiles (including the ‘generic’
directory), only in the system-dependent ‘Makefile’ in the specific
system’s subdirectory.

   If you come across a file that is in one of the main source
directories (‘string’, ‘stdio’, etc.), and you want to write a machine-
or operating system-dependent version of it, move the file into
‘sysdeps/generic’ and write your new implementation in the appropriate
system-specific subdirectory.  Note that if a file is to be
system-dependent, it *must not* appear in one of the main source
directories.

   There are a few special files that may exist in each subdirectory of
‘sysdeps’:

‘Makefile’

     A makefile for this machine or operating system, or class of
     machine or operating system.  This file is included by the library
     makefile ‘Makerules’, which is used by the top-level makefile and
     the subdirectory makefiles.  It can change the variables set in the
     including makefile or add new rules.  It can use GNU ‘make’
     conditional directives based on the variable ‘subdir’ (see above)
     to select different sets of variables and rules for different
     sections of the library.  It can also set the ‘make’ variable
     ‘sysdep-routines’, to specify extra modules to be included in the
     library.  You should use ‘sysdep-routines’ rather than adding
     modules to ‘routines’ because the latter is used in determining
     what to distribute for each subdirectory of the main source tree.

     Each makefile in a subdirectory in the ordered list of
     subdirectories to be searched is included in order.  Since several
     system-dependent makefiles may be included, each should append to
     ‘sysdep-routines’ rather than simply setting it:

          sysdep-routines := $(sysdep-routines) foo bar

‘Subdirs’

     This file contains the names of new whole subdirectories under the
     top-level library source tree that should be included for this
     system.  These subdirectories are treated just like the
     system-independent subdirectories in the library source tree, such
     as ‘stdio’ and ‘math’.

     Use this when there are completely new sets of functions and header
     files that should go into the library for the system this
     subdirectory of ‘sysdeps’ implements.  For example,
     ‘sysdeps/unix/inet/Subdirs’ contains ‘inet’; the ‘inet’ directory
     contains various network-oriented operations which only make sense
     to put in the library on systems that support the Internet.

‘configure’

     This file is a shell script fragment to be run at configuration
     time.  The top-level ‘configure’ script uses the shell ‘.’ command
     to read the ‘configure’ file in each system-dependent directory
     chosen, in order.  The ‘configure’ files are often generated from
     ‘configure.ac’ files using Autoconf.

     A system-dependent ‘configure’ script will usually add things to
     the shell variables ‘DEFS’ and ‘config_vars’; see the top-level
     ‘configure’ script for details.  The script can check for ‘--with-PACKAGE’
     options that were passed to the top-level ‘configure’.  For an
     option ‘--with-PACKAGE=VALUE’ ‘configure’ sets the shell variable ‘with_PACKAGE’
     (with any dashes in PACKAGE converted to underscores) to VALUE; if
     the option is just ‘--with-PACKAGE’ (no argument), then it sets ‘with_PACKAGE’
     to ‘yes’.

‘configure.ac’

     This file is an Autoconf input fragment to be processed into the
     file ‘configure’ in this subdirectory.  *Note
     (autoconf.info)Introduction::, for a description of Autoconf.  You
     should write either ‘configure’ or ‘configure.ac’, but not both.
     The first line of ‘configure.ac’ should invoke the ‘m4’ macro
     ‘GLIBC_PROVIDES’.  This macro does several ‘AC_PROVIDE’ calls for
     Autoconf macros which are used by the top-level ‘configure’ script;
     without this, those macros might be invoked again unnecessarily by
     Autoconf.

   That is the general system for how system-dependencies are isolated.

* Menu:

* Hierarchy Conventions::       The layout of the ‘sysdeps’ hierarchy.
* Porting to Unix::             Porting the library to an average
                                   Unix-like system.


File: libc.info,  Node: Hierarchy Conventions,  Next: Porting to Unix,  Up: Porting

D.3.1 Layout of the ‘sysdeps’ Directory Hierarchy
-------------------------------------------------

A GNU configuration name has three parts: the CPU type, the
manufacturer’s name, and the operating system.  ‘configure’ uses these
to pick the list of system-dependent directories to look for.  If the
‘--nfp’ option is _not_ passed to ‘configure’, the directory
‘MACHINE/fpu’ is also used.  The operating system often has a "base
operating system"; for example, if the operating system is ‘Linux’, the
base operating system is ‘unix/sysv’.  The algorithm used to pick the
list of directories is simple: ‘configure’ makes a list of the base
operating system, manufacturer, CPU type, and operating system, in that
order.  It then concatenates all these together with slashes in between,
to produce a directory name; for example, the configuration ‘i686-linux-gnu’
results in ‘unix/sysv/linux/i386/i686’.  ‘configure’ then tries removing
each element of the list in turn, so ‘unix/sysv/linux’ and ‘unix/sysv’
are also tried, among others.  Since the precise version number of the
operating system is often not important, and it would be very
inconvenient, for example, to have identical ‘irix6.2’ and ‘irix6.3’
directories, ‘configure’ tries successively less specific operating
system names by removing trailing suffixes starting with a period.

   As an example, here is the complete list of directories that would be
tried for the configuration ‘i686-linux-gnu’:

     sysdeps/i386/elf
     sysdeps/unix/sysv/linux/i386
     sysdeps/unix/sysv/linux
     sysdeps/gnu
     sysdeps/unix/common
     sysdeps/unix/mman
     sysdeps/unix/inet
     sysdeps/unix/sysv/i386/i686
     sysdeps/unix/sysv/i386
     sysdeps/unix/sysv
     sysdeps/unix/i386
     sysdeps/unix
     sysdeps/posix
     sysdeps/i386/i686
     sysdeps/i386/i486
     sysdeps/libm-i387/i686
     sysdeps/i386/fpu
     sysdeps/libm-i387
     sysdeps/i386
     sysdeps/wordsize-32
     sysdeps/ieee754
     sysdeps/libm-ieee754
     sysdeps/generic

   Different machine architectures are conventionally subdirectories at
the top level of the ‘sysdeps’ directory tree.  For example, ‘sysdeps/sparc’
and ‘sysdeps/m68k’.  These contain files specific to those machine
architectures, but not specific to any particular operating system.
There might be subdirectories for specializations of those
architectures, such as ‘sysdeps/m68k/68020’.  Code which is specific to
the floating-point coprocessor used with a particular machine should go
in ‘sysdeps/MACHINE/fpu’.

   There are a few directories at the top level of the ‘sysdeps’
hierarchy that are not for particular machine architectures.

‘generic’
     As described above (*note Porting::), this is the subdirectory that
     every configuration implicitly uses after all others.

‘ieee754’
     This directory is for code using the IEEE 754 floating-point
     format, where the C type ‘float’ is IEEE 754 single-precision
     format, and ‘double’ is IEEE 754 double-precision format.  Usually
     this directory is referred to in the ‘Implies’ file in a machine
     architecture-specific directory, such as ‘m68k/Implies’.

‘libm-ieee754’
     This directory contains an implementation of a mathematical library
     usable on platforms which use IEEE 754 conformant floating-point
     arithmetic.

‘libm-i387’
     This is a special case.  Ideally the code should be in
     ‘sysdeps/i386/fpu’ but for various reasons it is kept aside.

‘posix’
     This directory contains implementations of things in the library in
     terms of POSIX.1 functions.  This includes some of the POSIX.1
     functions themselves.  Of course, POSIX.1 cannot be completely
     implemented in terms of itself, so a configuration using just
     ‘posix’ cannot be complete.

‘unix’
     This is the directory for Unix-like things.  *Note Porting to
     Unix::.  ‘unix’ implies ‘posix’.  There are some special-purpose
     subdirectories of ‘unix’:

     ‘unix/common’
          This directory is for things common to both BSD and System V
          release 4.  Both ‘unix/bsd’ and ‘unix/sysv/sysv4’ imply
          ‘unix/common’.

     ‘unix/inet’
          This directory is for ‘socket’ and related functions on Unix
          systems.  ‘unix/inet/Subdirs’ enables the ‘inet’ top-level
          subdirectory.  ‘unix/common’ implies ‘unix/inet’.

‘mach’
     This is the directory for things based on the Mach microkernel from
     CMU (including GNU/Hurd systems).  Other basic operating systems
     (VMS, for example) would have their own directories at the top
     level of the ‘sysdeps’ hierarchy, parallel to ‘unix’ and ‘mach’.


File: libc.info,  Node: Porting to Unix,  Prev: Hierarchy Conventions,  Up: Porting

D.3.2 Porting the GNU C Library to Unix Systems
-----------------------------------------------

Most Unix systems are fundamentally very similar.  There are variations
between different machines, and variations in what facilities are
provided by the kernel.  But the interface to the operating system
facilities is, for the most part, pretty uniform and simple.

   The code for Unix systems is in the directory ‘unix’, at the top
level of the ‘sysdeps’ hierarchy.  This directory contains
subdirectories (and subdirectory trees) for various Unix variants.

   The functions which are system calls in most Unix systems are
implemented in assembly code, which is generated automatically from
specifications in files named ‘syscalls.list’.  There are several such
files, one in ‘sysdeps/unix’ and others in its subdirectories.  Some
special system calls are implemented in files that are named with a
suffix of ‘.S’; for example, ‘_exit.S’.  Files ending in ‘.S’ are run
through the C preprocessor before being fed to the assembler.

   These files all use a set of macros that should be defined in
‘sysdep.h’.  The ‘sysdep.h’ file in ‘sysdeps/unix’ partially defines
them; a ‘sysdep.h’ file in another directory must finish defining them
for the particular machine and operating system variant.  See
‘sysdeps/unix/sysdep.h’ and the machine-specific ‘sysdep.h’
implementations to see what these macros are and what they should do.

   The system-specific makefile for the ‘unix’ directory
(‘sysdeps/unix/Makefile’) gives rules to generate several files from the
Unix system you are building the library on (which is assumed to be the
target system you are building the library _for_).  All the generated
files are put in the directory where the object files are kept; they
should not affect the source tree itself.  The files generated are
‘ioctls.h’, ‘errnos.h’, ‘sys/param.h’, and ‘errlist.c’ (for the ‘stdio’
section of the library).


File: libc.info,  Node: Platform,  Next: Contributors,  Prev: Maintenance,  Up: Top

Appendix E Platform-specific facilities
***************************************

The GNU C Library can provide machine-specific functionality.

* Menu:

* PowerPC::           Facilities Specific to the PowerPC Architecture
* RISC-V::            Facilities Specific to the RISC-V Architecture
* X86::               Facilities Specific to the X86 Architecture


File: libc.info,  Node: PowerPC,  Next: RISC-V,  Up: Platform

E.1 PowerPC-specific Facilities
===============================

Facilities specific to PowerPC that are not specific to a particular
operating system are declared in ‘sys/platform/ppc.h’.

 -- Function: uint64_t __ppc_get_timebase (void)
     Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety
     Concepts::.

     Read the current value of the Time Base Register.

     The "Time Base Register" is a 64-bit register that stores a
     monotonically incremented value updated at a system-dependent
     frequency that may be different from the processor frequency.  More
     information is available in ‘Power ISA 2.06b - Book II - Section
     5.2’.

     ‘__ppc_get_timebase’ uses the processor’s time base facility
     directly without requiring assistance from the operating system, so
     it is very efficient.

 -- Function: uint64_t __ppc_get_timebase_freq (void)
     Preliminary: | MT-Unsafe init | AS-Unsafe corrupt:init | AC-Unsafe
     corrupt:init | *Note POSIX Safety Concepts::.

     Read the current frequency at which the Time Base Register is
     updated.

     This frequency is not related to the processor clock or the bus
     clock.  It is also possible that this frequency is not constant.
     More information is available in ‘Power ISA 2.06b - Book II -
     Section 5.2’.

   The following functions provide hints about the usage of resources
that are shared with other processors.  They can be used, for example,
if a program waiting on a lock intends to divert the shared resources to
be used by other processors.  More information is available in ‘Power
ISA 2.06b - Book II - Section 3.2’.

 -- Function: void __ppc_yield (void)
     Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety
     Concepts::.

     Provide a hint that performance will probably be improved if shared
     resources dedicated to the executing processor are released for use
     by other processors.

 -- Function: void __ppc_mdoio (void)
     Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety
     Concepts::.

     Provide a hint that performance will probably be improved if shared
     resources dedicated to the executing processor are released until
     all outstanding storage accesses to caching-inhibited storage have
     been completed.

 -- Function: void __ppc_mdoom (void)
     Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety
     Concepts::.

     Provide a hint that performance will probably be improved if shared
     resources dedicated to the executing processor are released until
     all outstanding storage accesses to cacheable storage for which the
     data is not in the cache have been completed.

 -- Function: void __ppc_set_ppr_med (void)
     Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety
     Concepts::.

     Set the Program Priority Register to medium value (default).

     The "Program Priority Register" (PPR) is a 64-bit register that
     controls the program’s priority.  By adjusting the PPR value the
     programmer may improve system throughput by causing the system
     resources to be used more efficiently, especially in contention
     situations.  The three unprivileged states available are covered by
     the functions ‘__ppc_set_ppr_med’ (medium – default),
     ‘__ppc_set_ppc_low’ (low) and ‘__ppc_set_ppc_med_low’ (medium low).
     More information available in ‘Power ISA 2.06b - Book II - Section
     3.1’.

 -- Function: void __ppc_set_ppr_low (void)
     Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety
     Concepts::.

     Set the Program Priority Register to low value.

 -- Function: void __ppc_set_ppr_med_low (void)
     Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety
     Concepts::.

     Set the Program Priority Register to medium low value.

   Power ISA 2.07 extends the priorities that can be set to the Program
Priority Register (PPR). The following functions implement the new
priority levels: very low and medium high.

 -- Function: void __ppc_set_ppr_very_low (void)
     Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety
     Concepts::.

     Set the Program Priority Register to very low value.

 -- Function: void __ppc_set_ppr_med_high (void)
     Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety
     Concepts::.

     Set the Program Priority Register to medium high value.  The medium
     high priority is privileged and may only be set during certain time
     intervals by problem-state programs.  If the program priority is
     medium high when the time interval expires or if an attempt is made
     to set the priority to medium high when it is not allowed, the
     priority is set to medium.


File: libc.info,  Node: RISC-V,  Next: X86,  Prev: PowerPC,  Up: Platform

E.2 RISC-V-specific Facilities
==============================

Cache management facilities specific to RISC-V systems that implement
the Linux ABI are declared in ‘sys/cachectl.h’.

 -- Function: void __riscv_flush_icache (void *START, void *END,
          unsigned long int FLAGS)
     Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety
     Concepts::.

     Enforce ordering between stores and instruction cache fetches.  The
     range of addresses over which ordering is enforced is specified by
     START and END.  The FLAGS argument controls the extent of this
     ordering, with the default behavior (a FLAGS value of 0) being to
     enforce the fence on all threads in the current process.  Setting
     the ‘SYS_RISCV_FLUSH_ICACHE_LOCAL’ bit allows users to indicate
     that enforcing ordering on only the current thread is necessary.
     All other flag bits are reserved.


File: libc.info,  Node: X86,  Prev: RISC-V,  Up: Platform

E.3 X86-specific Facilities
===========================

Facilities specific to X86 that are not specific to a particular
operating system are declared in ‘sys/platform/x86.h’.

 -- Function: const struct cpuid_feature * __x86_get_cpuid_feature_leaf
          (unsigned int LEAF)
     Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety
     Concepts::.

     Return a pointer to x86 CPU feature structure used by query macros
     for x86 CPU feature LEAF.

 -- Macro: int CPU_FEATURE_PRESENT (NAME)
     This macro returns a nonzero value (true) if the processor has the
     feature NAME.

 -- Macro: int CPU_FEATURE_ACTIVE (NAME)
     This macro returns a nonzero value (true) if the processor has the
     feature NAME and the feature is active.  There may be other
     preconditions, like sufficient stack space or further setup for
     AMX, which must be satisfied before the feature can be used.

   The supported processor features are:

   • ‘ACPI’ – Thermal Monitor and Software Controlled Clock Facilities.

   • ‘ADX’ – ADX instruction extensions.

   • ‘APIC’ – APIC On-Chip.

   • ‘AES’ – The AES instruction extensions.

   • ‘AESKLE’ – AES Key Locker instructions are enabled by OS.

   • ‘AMD_IBPB’ – Indirect branch predictor barrier (IBPB) for AMD cpus.

   • ‘AMD_IBRS’ – Indirect branch restricted speculation (IBPB) for AMD
     cpus.

   • ‘AMD_SSBD’ – Speculative Store Bypass Disable (SSBD) for AMD cpus.

   • ‘AMD_STIBP’ – Single thread indirect branch predictors (STIBP) for
     AMD cpus.

   • ‘AMD_VIRT_SSBD’ – Speculative Store Bypass Disable (SSBD) for AMD
     cpus (older systems).

   • ‘AMX_BF16’ – Tile computational operations on bfloat16 numbers.

   • ‘AMX_INT8’ – Tile computational operations on 8-bit numbers.

   • ‘AMX_TILE’ – Tile architecture.

   • ‘ARCH_CAPABILITIES’ – IA32_ARCH_CAPABILITIES MSR.

   • ‘AVX’ – The AVX instruction extensions.

   • ‘AVX2’ – The AVX2 instruction extensions.

   • ‘AVX_VNNI’ – The AVX-VNNI instruction extensions.

   • ‘AVX512_4FMAPS’ – The AVX512_4FMAPS instruction extensions.

   • ‘AVX512_4VNNIW’ – The AVX512_4VNNIW instruction extensions.

   • ‘AVX512_BF16’ – The AVX512_BF16 instruction extensions.

   • ‘AVX512_BITALG’ – The AVX512_BITALG instruction extensions.

   • ‘AVX512_FP16’ – The AVX512_FP16 instruction extensions.

   • ‘AVX512_IFMA’ – The AVX512_IFMA instruction extensions.

   • ‘AVX512_VBMI’ – The AVX512_VBMI instruction extensions.

   • ‘AVX512_VBMI2’ – The AVX512_VBMI2 instruction extensions.

   • ‘AVX512_VNNI’ – The AVX512_VNNI instruction extensions.

   • ‘AVX512_VP2INTERSECT’ – The AVX512_VP2INTERSECT instruction
     extensions.

   • ‘AVX512_VPOPCNTDQ’ – The AVX512_VPOPCNTDQ instruction extensions.

   • ‘AVX512BW’ – The AVX512BW instruction extensions.

   • ‘AVX512CD’ – The AVX512CD instruction extensions.

   • ‘AVX512ER’ – The AVX512ER instruction extensions.

   • ‘AVX512DQ’ – The AVX512DQ instruction extensions.

   • ‘AVX512F’ – The AVX512F instruction extensions.

   • ‘AVX512PF’ – The AVX512PF instruction extensions.

   • ‘AVX512VL’ – The AVX512VL instruction extensions.

   • ‘BMI1’ – BMI1 instructions.

   • ‘BMI2’ – BMI2 instructions.

   • ‘CLDEMOTE’ – CLDEMOTE instruction.

   • ‘CLFLUSHOPT’ – CLFLUSHOPT instruction.

   • ‘CLFSH’ – CLFLUSH instruction.

   • ‘CLWB’ – CLWB instruction.

   • ‘CMOV’ – Conditional Move instructions.

   • ‘CMPXCHG16B’ – CMPXCHG16B instruction.

   • ‘CNXT_ID’ – L1 Context ID.

   • ‘CORE_CAPABILITIES’ – IA32_CORE_CAPABILITIES MSR.

   • ‘CX8’ – CMPXCHG8B instruction.

   • ‘DCA’ – Data prefetch from a memory mapped device.

   • ‘DE’ – Debugging Extensions.

   • ‘DEPR_FPU_CS_DS’ – Deprecates FPU CS and FPU DS values.

   • ‘DS’ – Debug Store.

   • ‘DS_CPL’ – CPL Qualified Debug Store.

   • ‘DTES64’ – 64-bit DS Area.

   • ‘EIST’ – Enhanced Intel SpeedStep technology.

   • ‘ENQCMD’ – Enqueue Stores instructions.

   • ‘ERMS’ – Enhanced REP MOVSB/STOSB.

   • ‘F16C’ – 16-bit floating-point conversion instructions.

   • ‘FMA’ – FMA extensions using YMM state.

   • ‘FMA4’ – FMA4 instruction extensions.

   • ‘FPU’ – X87 Floating Point Unit On-Chip.

   • ‘FSGSBASE’ – RDFSBASE/RDGSBASE/WRFSBASE/WRGSBASE instructions.

   • ‘FSRCS’ – Fast Short REP CMP and SCA.

   • ‘FSRM’ – Fast Short REP MOV.

   • ‘FSRS’ – Fast Short REP STO.

   • ‘FXSR’ – FXSAVE and FXRSTOR instructions.

   • ‘FZLRM’ – Fast Zero-Length REP MOV.

   • ‘GFNI’ – GFNI instruction extensions.

   • ‘HLE’ – HLE instruction extensions.

   • ‘HTT’ – Max APIC IDs reserved field is Valid.

   • ‘HRESET’ – History reset.

   • ‘HYBRID’ – Hybrid processor.

   • ‘IBRS_IBPB’ – Indirect branch restricted speculation (IBRS) and the
     indirect branch predictor barrier (IBPB).

   • ‘IBT’ – Intel Indirect Branch Tracking instruction extensions.

   • ‘INVARIANT_TSC’ – Invariant TSC.

   • ‘INVPCID’ – INVPCID instruction.

   • ‘KL’ – AES Key Locker instructions.

   • ‘LAM’ – Linear Address Masking.

   • ‘L1D_FLUSH’ – IA32_FLUSH_CMD MSR.

   • ‘LAHF64_SAHF64’ – LAHF/SAHF available in 64-bit mode.

   • ‘LM’ – Long mode.

   • ‘LWP’ – Lightweight profiling.

   • ‘LZCNT’ – LZCNT instruction.

   • ‘MCA’ – Machine Check Architecture.

   • ‘MCE’ – Machine Check Exception.

   • ‘MD_CLEAR’ – MD_CLEAR.

   • ‘MMX’ – Intel MMX Technology.

   • ‘MONITOR’ – MONITOR/MWAIT instructions.

   • ‘MOVBE’ – MOVBE instruction.

   • ‘MOVDIRI’ – MOVDIRI instruction.

   • ‘MOVDIR64B’ – MOVDIR64B instruction.

   • ‘MPX’ – Intel Memory Protection Extensions.

   • ‘MSR’ – Model Specific Registers RDMSR and WRMSR instructions.

   • ‘MTRR’ – Memory Type Range Registers.

   • ‘NX’ – No-execute page protection.

   • ‘OSPKE’ – OS has set CR4.PKE to enable protection keys.

   • ‘OSXSAVE’ – The OS has set CR4.OSXSAVE[bit 18] to enable
     XSETBV/XGETBV instructions to access XCR0 and to support processor
     extended state management using XSAVE/XRSTOR.

   • ‘PAE’ – Physical Address Extension.

   • ‘PAGE1GB’ – 1-GByte page.

   • ‘PAT’ – Page Attribute Table.

   • ‘PBE’ – Pending Break Enable.

   • ‘PCID’ – Process-context identifiers.

   • ‘PCLMULQDQ’ – PCLMULQDQ instruction.

   • ‘PCONFIG’ – PCONFIG instruction.

   • ‘PDCM’ – Perfmon and Debug Capability.

   • ‘PGE’ – Page Global Bit.

   • ‘PKS’ – Protection keys for supervisor-mode pages.

   • ‘PKU’ – Protection keys for user-mode pages.

   • ‘POPCNT’ – POPCNT instruction.

   • ‘PREFETCHW’ – PREFETCHW instruction.

   • ‘PREFETCHWT1’ – PREFETCHWT1 instruction.

   • ‘PSE’ – Page Size Extension.

   • ‘PSE_36’ – 36-Bit Page Size Extension.

   • ‘PSN’ – Processor Serial Number.

   • ‘PTWRITE’ – PTWRITE instruction.

   • ‘RDPID’ – RDPID instruction.

   • ‘RDRAND’ – RDRAND instruction.

   • ‘RDSEED’ – RDSEED instruction.

   • ‘RDT_A’ – Intel Resource Director Technology (Intel RDT) Allocation
     capability.

   • ‘RDT_M’ – Intel Resource Director Technology (Intel RDT) Monitoring
     capability.

   • ‘RDTSCP’ – RDTSCP instruction.

   • ‘RTM’ – RTM instruction extensions.

   • ‘RTM_ALWAYS_ABORT’ – Transactions always abort, making RTM
     unusable.

   • ‘SDBG’ – IA32_DEBUG_INTERFACE MSR for silicon debug.

   • ‘SEP’ – SYSENTER and SYSEXIT instructions.

   • ‘SERIALIZE’ – SERIALIZE instruction.

   • ‘SGX’ – Intel Software Guard Extensions.

   • ‘SGX_LC’ – SGX Launch Configuration.

   • ‘SHA’ – SHA instruction extensions.

   • ‘SHSTK’ – Intel Shadow Stack instruction extensions.

   • ‘SMAP’ – Supervisor-Mode Access Prevention.

   • ‘SMEP’ – Supervisor-Mode Execution Prevention.

   • ‘SMX’ – Safer Mode Extensions.

   • ‘SS’ – Self Snoop.

   • ‘SSBD’ – Speculative Store Bypass Disable (SSBD).

   • ‘SSE’ – Streaming SIMD Extensions.

   • ‘SSE2’ – Streaming SIMD Extensions 2.

   • ‘SSE3’ – Streaming SIMD Extensions 3.

   • ‘SSE4_1’ – Streaming SIMD Extensions 4.1.

   • ‘SSE4_2’ – Streaming SIMD Extensions 4.2.

   • ‘SSE4A’ – SSE4A instruction extensions.

   • ‘SSSE3’ – Supplemental Streaming SIMD Extensions 3.

   • ‘STIBP’ – Single thread indirect branch predictors (STIBP).

   • ‘SVM’ – Secure Virtual Machine.

   • ‘SYSCALL_SYSRET’ – SYSCALL/SYSRET instructions.

   • ‘TBM’ – Trailing bit manipulation instructions.

   • ‘TM’ – Thermal Monitor.

   • ‘TM2’ – Thermal Monitor 2.

   • ‘TRACE’ – Intel Processor Trace.

   • ‘TSC’ – Time Stamp Counter.  RDTSC instruction.

   • ‘TSC_ADJUST’ – IA32_TSC_ADJUST MSR.

   • ‘TSC_DEADLINE’ – Local APIC timer supports one-shot operation using
     a TSC deadline value.

   • ‘TSXLDTRK’ – TSXLDTRK instructions.

   • ‘UINTR’ – User interrupts.

   • ‘UMIP’ – User-mode instruction prevention.

   • ‘VAES’ – VAES instruction extensions.

   • ‘VME’ – Virtual 8086 Mode Enhancements.

   • ‘VMX’ – Virtual Machine Extensions.

   • ‘VPCLMULQDQ’ – VPCLMULQDQ instruction.

   • ‘WAITPKG’ – WAITPKG instruction extensions.

   • ‘WBNOINVD’ – WBINVD/WBNOINVD instructions.

   • ‘WIDE_KL’ – AES wide Key Locker instructions.

   • ‘X2APIC’ – x2APIC.

   • ‘XFD’ – Extended Feature Disable (XFD).

   • ‘XGETBV_ECX_1’ – XGETBV with ECX = 1.

   • ‘XOP’ – XOP instruction extensions.

   • ‘XSAVE’ – The XSAVE/XRSTOR processor extended states feature, the
     XSETBV/XGETBV instructions, and XCR0.

   • ‘XSAVEC’ – XSAVEC instruction.

   • ‘XSAVEOPT’ – XSAVEOPT instruction.

   • ‘XSAVES’ – XSAVES/XRSTORS instructions.

   • ‘XTPRUPDCTRL’ – xTPR Update Control.

   You could query if a processor supports ‘AVX’ with:

     #include <sys/platform/x86.h>

     int
     avx_present (void)
     {
       return CPU_FEATURE_PRESENT (AVX);
     }

   and if ‘AVX’ is active and may be used with:

     #include <sys/platform/x86.h>

     int
     avx_active (void)
     {
       return CPU_FEATURE_ACTIVE (AVX);
     }


File: libc.info,  Node: Contributors,  Next: Free Manuals,  Prev: Platform,  Up: Top

Appendix F Contributors to the GNU C Library
********************************************

The GNU C Library project would like to thank its many contributors.
Without them the project would not have been nearly as successful as it
has been.  Any omissions in this list are accidental.  Feel free to file
a bug in bugzilla if you have been left out or some of your
contributions are not listed.  Please keep this list in alphabetical
order.

   • Nick Alcock for contributing fixes to allow the GNU C Library to be
     built with the stack smashing protector enabled.

   • John David Anglin for various fixes to the hppa port.

   • Albert ARIBAUD for Y2038 related fixes.

   • Ryan S. Arnold for his improvements for Linux on PowerPC and his
     direction as FSF Project Steward for the GNU C Library.

   • Miles Bader for writing the ‘argp’ argument-parsing package, and
     the ‘argz’/‘envz’ interfaces.

   • Ralf Bächle for contributing ‘fpu_control.h’, ‘regdef.h’,
     ‘sgidefs.h’, ‘sys/asm.h’, and ‘sys/regdef.h’ under the
     ‘sysdeps/mips’ directory.

   • Jeff Bailey for his maintainership of the HPPA architecture.

   • Petr Baudis for bug fixes and testing.

   • Anton Blanchard for various fixes.

   • Stephen R. van den Berg for contributing a highly-optimized
     ‘strstr’ function.

   • Ondřej Bílka for contributing optimized string routines for x64 and
     various fixes.

   • Eric Blake for adding O(n) implementations of ‘memmem’, ‘strstr’
     and ‘strcasestr’.

   • Philip Blundell for the ports to Linux/ARM
     (‘arm-ANYTHING-linuxaout’) and ARM standalone
     (‘arm-ANYTHING-none’), as well as for parts of the IPv6 support
     code.

   • Per Bothner for the implementation of the ‘libio’ library which is
     used to implement ‘stdio’ functions.

   • Mark Brown for his direction as part of the GNU C Library steering
     committee.

   • Thomas Bushnell for his contributions to Hurd.

   • Rogerio Alves Cardoso for various fixes to PowerPC.

   • Paul Clarke for optimized functions on PowerPC.

   • Mike Crowe for various fixes.

   • Palmer Dabbelt for contributing the port to Linux/RISC-V.

   • DJ Delorie for maintenance of Linux/RISC-V, and various fixes.

   • Wilco Dijkstra for various fixes.

   • Liubov Dmitrieva for optimized string and math functions on x86-64
     and x86.

   • Ulrich Drepper for his many contributions in almost all parts of
     the GNU C Library, including:
        • writing most of the POSIX Threads Library originally.
        • internationalization support, including the ‘locale’ and
          ‘localedef’ utilities.
        • Linux i386/ELF support
        • the ‘hsearch’ and ‘drand48’ families of functions, reentrant
          ‘…‘_r’’ versions of the ‘random’ family; System V shared
          memory and IPC support code
        • several highly-optimized string functions for iX86 processors
        • many math functions
        • the character conversion functions (‘iconv’)
        • the ‘ftw’ and ‘nftw’ functions
        • the floating-point printing function used by ‘printf’ and
          friends and the floating-point reading function used by
          ‘scanf’, ‘strtod’ and friends
        • the ‘catgets’ support and the entire suite of multi-byte and
          wide-character support functions (‘wctype.h’, ‘wchar.h’,
          etc.).
        • versioning of objects on the symbol level

   • Richard Earnshaw for continued support and fixes to the various ARM
     machine files.

   • Paul Eggert for the ‘mktime’ function and for his direction as part
     of the GNU C Library steering committee.

   • Steve Ellcey for various fixes.

   • Mike FABIAN for automating Unicode updates, for updating the locale
     data for ISO 14651, for updating the library Unicode support, and
     for various locale updates and fixes.

   • Tulio Magno Quites Machado Filho for adding a new class of
     installed headers for low-level platform-specific functionality and
     one such for PowerPC and various fixes.

   • Olaf Flebbe and Ralf Bächle for contributing
     ‘sysdeps/mips/fpu_control.h’.

   • Alistair Francis for Y2038 related fixes.

   • Mike Frysinger for his maintaining of the IA64 architecture and for
     testing and bug fixing.

   • Martin Galvan for contributing gdb pretty printer support to glibc
     and adding an initial set of pretty printers for structures in the
     POSIX Threads library.

   • Michael Glad for the passphrase-hashing function ‘crypt’ and
     related functions.

   • Wolfram Gloger for contributing the memory allocation functions
     functions ‘malloc’, ‘realloc’ and ‘free’ and related code.

   • Gabriel F. T. Gomes for his improvements for Linux on PowerPC and
     for implementing the IEEE 128-bit floating point type for PowerPC.

   • Torbjörn Granlund for fast implementations of many of the string
     functions (‘memcpy’, ‘strlen’, etc.).

   • Michael J. Haertel for writing the merge sort function ‘qsort’ and
     malloc checking functions like ‘mcheck’.

   • Bruno Haible for his improvements to the ‘iconv’ and locale
     implementations.

   • Mao Han for the C-SKY port.

   • Richard Henderson for the port to Linux on Alpha
     (‘alpha-ANYTHING-linux’) and software floating-point support.

   • David Holsgrove for the port to Linux on MicroBlaze.

   • Leonhard Holz for various fixes.

   • Daniel Jacobowitz for various fixes and enhancements.

   • Andreas Jaeger for the port to Linux on x86-64
     (‘x86_64-ANYTHING-linux’ and his work on Linux for MIPS
     (‘mips-ANYTHING-linux’), implementing the ‘ldconfig’ program,
     providing a test suite for the math library and for his direction
     as part of the GNU C Library steering committee.

   • Aurelien Jarno for various fixes.

   • Rical Jasan for contributing various fixes in the GNU C Library
     manual.

   • Jakub Jelinek for implementing a number of checking functions,
     software floating-point support and for his direction as part of
     the GNU C Library steering committee.

   • Simon Josefsson for the ‘libidn’ add-on.

   • Geoffrey Keating for the port to Linux on PowerPC
     (‘powerpc-ANYTHING-linux’).

   • Brendan Kehoe for contributing the port to the MIPS DECStation
     running Ultrix 4 (‘mips-dec-ultrix4’) and the port to the DEC Alpha
     running OSF/1 (‘alpha-dec-osf1’).

   • Mark Kettenis for implementing the ‘utmpx’ interface and a utmp
     daemon, and for a Hesiod NSS module.

   • Andi Kleen for implementing pthreads lock elision with TSX.

   • Kazumoto Kojima for the port of the Mach and Hurd code to the MIPS
     architecture (‘mips-ANYTHING-gnu’) and for his work on the SH
     architecture.

   • Maxim Kuvyrkov for various fixes.

   • Andreas Krebbel for his work on Linux for s390 and s390x.

   • Thorsten Kukuk for providing an implementation for NIS (YP) and
     NIS+, securelevel 0, 1 and 2 and for the implementation for a
     caching daemon for NSS (‘nscd’).

   • Akhilesh Kumar for various fixes to locales.

   • Jeff Law for various fixes.

   • Doug Lea for contributing the memory allocation functions ‘malloc’,
     ‘realloc’ and ‘free’ and related code.

   • Chris Leonard for various fixes and enhancements to localedata.

   • Ilya Leoshkevich for various fixes.

   • Dmitry V. Levin for various fixes.

   • Stefan Liebler for various fixes.

   • Hongjiu Lu for providing the support for a Linux 32-bit runtime
     environment under x86-64 (x32), for porting to Linux on IA64, for
     improved string functions, a framework for testing IFUNC
     implementations, for implementing Intel Control-Flow Enforcement
     Technology, and many bug fixes.

   • Rafał Lużyński for contributing support for two grammatical forms
     of month names, and for various fixes to locales.

   • Luis Machado for optimized functions on PowerPC.

   • David J. MacKenzie for his contribution to the ‘getopt’ function
     and writing the ‘tar.h’ header.

   • Lukasz Majewski for Y2038 related fixes.

   • Greg McGary for adding runtime support for bounds checking.

   • Roland McGrath for writing most of the GNU C Library originally,
     for his work on the Hurd port, his direction as part of the GNU C
     Library steering committee and as FSF Project Steward for the GNU C
     Library, and for many bug fixes and reviewing of contributions.

   • Allan McRae for various fixes.

   • Jason Merrill for the port to the Sequent Symmetry running Dynix
     version 3 (‘i386-sequent-bsd’).

   • Chris Metcalf for the port to Linux/Tile (‘tilegx-ANYTHING-linux’
     and ‘tilepro-ANYTHING-linux’) and support for the generic Linux
     kernel syscall interface used by several newer ports.

   • Jim Meyering for various fixes.

   • David Miller for contributing the port to Linux/Sparc
     (‘sparc*-ANYTHING-linux’).

   • Alan Modra for his improvements for Linux on PowerPC.

   • David Mosberger-Tang for contributing the port to Linux/Alpha
     (‘alpha-ANYTHING-linux’).

   • Wainer dos Santos Moschetta for various fixes to powerpc.

   • Stephen Moshier for implementing some 128-bit long double format
     math functions.

   • Stephen Munroe for his port to Linux on PowerPC64
     (‘powerpc64-ANYTHING-linux’) and for adding optimized
     implementations for PowerPC.

   • Paul E. Murphy for various fixes on PowerPC and for implementing
     the IEEE 128-bit floating point type for PowerPC.

   • Joseph S. Myers for numerous bug fixes for the libm functions, for
     his maintainership of the ARM and MIPS architectures and the math
     component, improving cross-compilation and cross-testing of the GNU
     C Library, expanded coverage of conformtest, merging the ports/
     subdirectory into the GNU C Library main repository and his
     direction as FSF Project Steward for the GNU C Library.

   • Marko Myllynen for various fixes.

   • Szabolcs Nagy for various fixes.

   • Will Newton for contributing some optimized string functions and
     pointer encryption support for ARM and various fixes.

   • Carlos O’Donell for his maintainership of the HPPA architecture,
     for maintaining the GNU C Library web pages and wiki, for his
     direction as FSF Project Steward for the GNU C Library and various
     bug fixes.

   • Alexandre Oliva for adding TLS descriptors for LD and GD on x86 and
     x86-64, for the am33 port, for completing the MIPS n64/n32/o32
     multilib port, for thread-safety, async-signal safety and
     async-cancellation safety documentation in the manual, for his
     direction as FSF Project Maintainer and for various fixes.

   • Paul Pluzhnikov for various fixes.

   • Marek Polacek for various fixes.

   • Siddhesh Poyarekar for various fixes, an implementation of a
     framework for performance benchmarking of functions and
     implementing the tunables infrastructure.

   • Tom Quinn for contributing the startup code to support SunOS shared
     libraries and the port to SGI machines running Irix 4
     (‘mips-sgi-irix4’).

   • Torvald Riegel for the implementation of new algorithms for
     semaphores, pthread_rwlock and condition variables.

   • Maciej W. Rozycki for MIPS fixes, support for ABSOLUTE symbols, and
     various fixes.

   • Leonardo Sandoval for various fixes.

   • Pravin Satpute for writing sorting rules for some Indian languages.

   • Douglas C. Schmidt for writing the quick sort function used as a
     fallback by ‘qsort’.

   • Will Schmidt for optimized string functions on PowerPC.

   • Andreas Schwab for the port to Linux/m68k (‘m68k-ANYTHING-linux’),
     for his direction as part of the GNU C Library steering committee,
     and for various bug fixes.

   • Martin Schwidefsky for porting to Linux on s390
     (‘s390-ANYTHING-linux’) and s390x (‘s390x-ANYTHING-linux’).

   • Thomas Schwinge for his contribution to Hurd and the SH
     architecture.

   • Martin Sebor for various fixes.

   • Andrew Senkevich for contributing vector math function
     implementations for x86.

   • Carlos Eduardo Seo for optimized functions on PowerPC.

   • Arjun Shankar for testing and bug fixing.

   • Marcus Shawcroft for contributing the AArch64 port.

   • TAMUKI Shoichi for various fixes.

   • Franz Sirl for various fixes.

   • Jes Sorensen for porting to Linux on IA64 (‘ia64-ANYTHING-linux’).

   • Rajalakshmi Srinivasaraghavan for various fixes and optimizations
     on PowerPC and for implementing the IEEE 128-bit floating point
     type for PowerPC.

   • Richard Stallman for his contribution to the ‘getopt’ function.

   • Alfred M. Szmidt for various fixes.

   • Chung-Lin Tang for contributing the Nios II port.

   • Ian Lance Taylor for contributing the port to the MIPS DECStation
     running Ultrix 4 (‘mips-dec-ultrix4’).

   • Samuel Thibault for improving the Hurd port.

   • Pino Toscano for various fixes.

   • Matt Turner for various fixes to the Alpha port.

   • Tim Waugh for the implementation of the POSIX.2 ‘wordexp’ function
     family.

   • Ulrich Weigand for various fixes to the PowerPC64 and Arm ports.

   • Florian Weimer for his maintainership of the network component, for
     handling of security issues, and for various fixes.

   • Zack Weinberg for the ‘explicit_bzero’ implementation and for
     various fixes.

   • Mark Wielaard for various fixes.

   • Eric Youngdale for implementing versioning of objects on the symbol
     level.

   • Adhemerval Zanella for optimized functions on PowerPC, ISO C
     threads support and various fixes.

   • Xuelei Zhang for optimized functions on AArch64.

   Some code in the GNU C Library comes from other projects and might be
under a different license:

   • The timezone support code is derived from the public-domain
     timezone package by Arthur David Olson and his many contributors.

   • Some of the support code for Mach is taken from Mach 3.0 by CMU;
     the file ‘if_ppp.h’ is also copyright by CMU, but under a different
     license; see the file ‘LICENSES’ for the text of the licenses.

   • The random number generation functions ‘random’, ‘srandom’,
     ‘setstate’ and ‘initstate’, which are also the basis for the ‘rand’
     and ‘srand’ functions, were written by Earl T. Cohen for the
     University of California at Berkeley and are copyrighted by the
     Regents of the University of California.  They have undergone minor
     changes to fit into the GNU C Library and to fit the ISO C
     standard, but the functional code is Berkeley’s.

   • The Internet-related code (most of the ‘inet’ subdirectory) and
     several other miscellaneous functions and header files have been
     included from 4.4 BSD with little or no modification.  The copying
     permission notice for this code can be found in the file ‘LICENSES’
     in the source distribution.

   • The ‘getaddrinfo’ and ‘getnameinfo’ functions and supporting code
     were written by Craig Metz; see the file ‘LICENSES’ for details on
     their licensing.

   • The DNS resolver code is taken directly from BIND 8.2.3-T5B, which
     includes copyrighted code from UC Berkeley and from Digital
     Equipment Corporation.  See the file ‘LICENSES’ for the text of the
     DEC license.

   • The code to support Sun RPC is taken verbatim from Sun’s RPCSRC-4.0
     distribution; see the file ‘LICENSES’ for the text of the license.

   • The math functions are taken from ‘fdlibm-5.1’ by Sun Microsystems,
     as modified by J.T. Conklin, Ian Lance Taylor, Ulrich Drepper,
     Andreas Schwab, and Roland McGrath.

   • Many of the IEEE 64-bit double precision math functions (in the
     ‘sysdeps/ieee754/dbl-64’ subdirectory) come from the IBM Accurate
     Mathematical Library, contributed by IBM.

   • Many of the IA64 math functions are taken from a collection of
     “Highly Optimized Mathematical Functions for Itanium” that Intel
     makes available under a free license; see the file ‘LICENSES’ for
     details.


File: libc.info,  Node: Free Manuals,  Next: Copying,  Prev: Contributors,  Up: Top

Appendix G Free Software Needs Free Documentation
*************************************************

The biggest deficiency in the free software community today is not in
the software—it is the lack of good free documentation that we can
include with the free software.  Many of our most important programs do
not come with free reference manuals and free introductory texts.
Documentation is an essential part of any software package; when an
important free software package does not come with a free manual and a
free tutorial, that is a major gap.  We have many such gaps today.

   Consider Perl, for instance.  The tutorial manuals that people
normally use are non-free.  How did this come about?  Because the
authors of those manuals published them with restrictive terms—no
copying, no modification, source files not available—which exclude them
from the free software world.

   That wasn’t the first time this sort of thing happened, and it was
far from the last.  Many times we have heard a GNU user eagerly describe
a manual that he is writing, his intended contribution to the community,
only to learn that he had ruined everything by signing a publication
contract to make it non-free.

   Free documentation, like free software, is a matter of freedom, not
price.  The problem with the non-free manual is not that publishers
charge a price for printed copies—that in itself is fine.  (The Free
Software Foundation sells printed copies of manuals, too.)  The problem
is the restrictions on the use of the manual.  Free manuals are
available in source code form, and give you permission to copy and
modify.  Non-free manuals do not allow this.

   The criteria of freedom for a free manual are roughly the same as for
free software.  Redistribution (including the normal kinds of commercial
redistribution) must be permitted, so that the manual can accompany
every copy of the program, both on-line and on paper.

   Permission for modification of the technical content is crucial too.
When people modify the software, adding or changing features, if they
are conscientious they will change the manual too—so they can provide
accurate and clear documentation for the modified program.  A manual
that leaves you no choice but to write a new manual to document a
changed version of the program is not really available to our community.

   Some kinds of limits on the way modification is handled are
acceptable.  For example, requirements to preserve the original author’s
copyright notice, the distribution terms, or the list of authors, are
ok.  It is also no problem to require modified versions to include
notice that they were modified.  Even entire sections that may not be
deleted or changed are acceptable, as long as they deal with
nontechnical topics (like this one).  These kinds of restrictions are
acceptable because they don’t obstruct the community’s normal use of the
manual.

   However, it must be possible to modify all the _technical_ content of
the manual, and then distribute the result in all the usual media,
through all the usual channels.  Otherwise, the restrictions obstruct
the use of the manual, it is not free, and we need another manual to
replace it.

   Please spread the word about this issue.  Our community continues to
lose manuals to proprietary publishing.  If we spread the word that free
software needs free reference manuals and free tutorials, perhaps the
next person who wants to contribute by writing documentation will
realize, before it is too late, that only free manuals contribute to the
free software community.

   If you are writing documentation, please insist on publishing it
under the GNU Free Documentation License or another free documentation
license.  Remember that this decision requires your approval—you don’t
have to let the publisher decide.  Some commercial publishers will use a
free license if you insist, but they will not propose the option; it is
up to you to raise the issue and say firmly that this is what you want.
If the publisher you are dealing with refuses, please try other
publishers.  If you’re not sure whether a proposed license is free,
write to <licensing@gnu.org>.

   You can encourage commercial publishers to sell more free, copylefted
manuals and tutorials by buying them, and particularly by buying copies
from the publishers that paid for their writing or for major
improvements.  Meanwhile, try to avoid buying non-free documentation at
all.  Check the distribution terms of a manual before you buy it, and
insist that whoever seeks your business must respect your freedom.
Check the history of the book, and try reward the publishers that have
paid or pay the authors to work on it.

   The Free Software Foundation maintains a list of free documentation
published by other publishers, at
<https://www.fsf.org/doc/other-free-books.html>.