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authorRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
committerRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
commit28f540f45bbacd939bfd07f213bcad2bf730b1bf (patch)
tree15f07c4c43d635959c6afee96bde71fb1b3614ee /posix/unistd.h
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+/* Copyright (C) 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+/*
+ *	POSIX Standard: 2.10 Symbolic Constants		<unistd.h>
+ */
+
+#ifndef	_UNISTD_H
+
+#define	_UNISTD_H	1
+#include <features.h>
+
+__BEGIN_DECLS
+
+/* These may be used to determine what facilities are present at compile time.
+   Their values can be obtained at run time from sysconf.  */
+
+/* POSIX Standard approved as IEEE Std 1003.1 as of August, 1988.  */
+#define	_POSIX_VERSION	199009L
+
+/* These are not #ifdef __USE_POSIX2 because they are
+   in the theoretically application-owned namespace.  */
+
+#define	_POSIX2_C_VERSION	199912L	/* Invalid until 1003.2 is done.  */
+
+/* If defined, the implementation supports the
+   C Language Bindings Option.  */
+#define	_POSIX2_C_BIND	1
+
+/* If defined, the implementation supports the
+   C Language Development Utilities Option.  */
+#define	_POSIX2_C_DEV	1
+
+/* If defined, the implementation supports the
+   Software Development Utilities Option.  */
+#define	_POSIX2_SW_DEV	1
+
+
+/* Get values of POSIX options:
+
+   If these symbols are defined, the corresponding features are
+   always available.  If not, they may be available sometimes.
+   The current values can be obtained with `sysconf'.
+
+   _POSIX_JOB_CONTROL	Job control is supported.
+   _POSIX_SAVED_IDS	Processes have a saved set-user-ID
+   			and a saved set-group-ID.
+
+   If any of these symbols is defined as -1, the corresponding option is not
+   true for any file.  If any is defined as other than -1, the corresponding
+   option is true for all files.  If a symbol is not defined at all, the value
+   for a specific file can be obtained from `pathconf' and `fpathconf'.
+
+   _POSIX_CHOWN_RESTRICTED	Only the super user can use `chown' to change
+   				the owner of a file.  `chown' can only be used
+				to change the group ID of a file to a group of
+				which the calling process is a member.
+   _POSIX_NO_TRUNC		Pathname components longer than
+   				NAME_MAX generate an error.
+   _POSIX_VDISABLE		If defined, if the value of an element of the
+				`c_cc' member of `struct termios' is
+				_POSIX_VDISABLE, no character will have the
+				effect associated with that element.
+   */
+
+#include <posix_opt.h>
+
+
+/* Standard file descriptors.  */
+#define	STDIN_FILENO	0	/* Standard input.  */
+#define	STDOUT_FILENO	1	/* Standard output.  */
+#define	STDERR_FILENO	2	/* Standard error output.  */
+
+
+/* All functions that are not declared anywhere else.  */
+
+#include <gnu/types.h>
+
+#ifndef	ssize_t
+#define	ssize_t	__ssize_t
+#endif
+
+#define	__need_size_t
+#define __need_NULL
+#include <stddef.h>
+
+
+/* Values for the second argument to access.
+   These may be OR'd together.  */
+#define	R_OK	4		/* Test for read permission.  */
+#define	W_OK	2		/* Test for write permission.  */
+#define	X_OK	1		/* Test for execute permission.  */
+#define	F_OK	0		/* Test for existence.  */
+
+/* Test for access to NAME.  */
+extern int __access __P ((__const char *__name, int __type));
+extern int access __P ((__const char *__name, int __type));
+
+
+/* Values for the WHENCE argument to lseek.  */
+#ifndef	_STDIO_H		/* <stdio.h> has the same definitions.  */
+#define	SEEK_SET	0	/* Seek from beginning of file.  */
+#define	SEEK_CUR	1	/* Seek from current position.  */
+#define	SEEK_END	2	/* Seek from end of file.  */
+#endif
+
+/* Move FD's file position to OFFSET bytes from the
+   beginning of the file (if WHENCE is SEEK_SET),
+   the current position (if WHENCE is SEEK_CUR),
+   or the end of the file (if WHENCE is SEEK_END).
+   Return the new file position.  */
+extern __off_t __lseek __P ((int __fd, __off_t __offset, int __whence));
+extern __off_t lseek __P ((int __fd, __off_t __offset, int __whence));
+
+/* Close the file descriptor FD.  */
+extern int __close __P ((int __fd));
+extern int close __P ((int __fd));
+
+/* Read NBYTES into BUF from FD.  Return the
+   number read, -1 for errors or 0 for EOF.  */
+extern ssize_t __read __P ((int __fd, __ptr_t __buf, size_t __nbytes));
+extern ssize_t read __P ((int __fd, __ptr_t __buf, size_t __nbytes));
+
+/* Write N bytes of BUF to FD.  Return the number written, or -1.  */
+extern ssize_t __write __P ((int __fd, __const __ptr_t __buf, size_t __n));
+extern ssize_t write __P ((int __fd, __const __ptr_t __buf, size_t __n));
+
+
+/* Create a one-way communication channel (pipe).
+   If successul, two file descriptors are stored in PIPEDES;
+   bytes written on PIPEDES[1] can be read from PIPEDES[0].
+   Returns 0 if successful, -1 if not.  */
+extern int __pipe __P ((int __pipedes[2]));
+extern int pipe __P ((int __pipedes[2]));
+
+/* Schedule an alarm.  In SECONDS seconds, the process will get a SIGALRM.
+   If SECONDS is zero, any currently scheduled alarm will be cancelled.
+   The function returns the number of seconds remaining until the last
+   alarm scheduled would have signaled, or zero if there wasn't one.
+   There is no return value to indicate an error, but you can set `errno'
+   to 0 and check its value after calling `alarm', and this might tell you.
+   The signal may come late due to processor scheduling.  */
+extern unsigned int alarm __P ((unsigned int __seconds));
+
+/* Make the process sleep for SECONDS seconds, or until a signal arrives
+   and is not ignored.  The function returns the number of seconds less
+   than SECONDS which it actually slept (thus zero if it slept the full time).
+   If a signal handler does a `longjmp' or modifies the handling of the
+   SIGALRM signal while inside `sleep' call, the handling of the SIGALRM
+   signal afterwards is undefined.  There is no return value to indicate
+   error, but if `sleep' returns SECONDS, it probably didn't work.  */
+extern unsigned int sleep __P ((unsigned int __seconds));
+
+
+/* Suspend the process until a signal arrives.
+   This always returns -1 and sets `errno' to EINTR.  */
+extern int pause __P ((void));
+
+
+/* Change the owner and group of FILE.  */
+extern int __chown __P ((__const char *__file,
+			 __uid_t __owner, __gid_t __group));
+extern int chown __P ((__const char *__file,
+		       __uid_t __owner, __gid_t __group));
+
+#ifdef	__USE_BSD
+/* Change the owner and group of the file that FD is open on.  */
+extern int __fchown __P ((int __fd,
+			  __uid_t __owner, __gid_t __group));
+extern int fchown __P ((int __fd,
+			__uid_t __owner, __gid_t __group));
+#endif /* Use BSD.  */
+
+/* Change the process's working directory to PATH.  */
+extern int __chdir __P ((__const char *__path));
+extern int chdir __P ((__const char *__path));
+
+#ifdef __USE_BSD
+/* Change the process's working directory to the one FD is open on.  */
+extern int fchdir __P ((int __fd));
+#endif
+
+/* Get the pathname of the current working directory,
+   and put it in SIZE bytes of BUF.  Returns NULL if the
+   directory couldn't be determined or SIZE was too small.
+   If successful, returns BUF.  In GNU, if BUF is NULL,
+   an array is allocated with `malloc'; the array is SIZE
+   bytes long, unless SIZE <= 0, in which case it is as
+   big as necessary.  */
+extern char *getcwd __P ((char *__buf, size_t __size));
+
+#ifdef	__USE_GNU
+/* Return a malloc'd string containing the current directory name.
+   If the environment variable `PWD' is set, and its value is correct,
+   that value is used.  */
+extern char *get_current_dir_name __P ((void));
+#endif
+
+#ifdef	__USE_BSD
+/* Put the absolute pathname of the current working directory in BUF.
+   If successful, return BUF.  If not, put an error message in
+   BUF and return NULL.  BUF should be at least PATH_MAX bytes long.  */
+extern char *getwd __P ((char *__buf));
+#endif
+
+
+/* Duplicate FD, returning a new file descriptor on the same file.  */
+extern int __dup __P ((int __fd));
+extern int dup __P ((int __fd));
+
+/* Duplicate FD to FD2, closing FD2 and making it open on the same file.  */
+extern int __dup2 __P ((int __fd, int __fd2));
+extern int dup2 __P ((int __fd, int __fd2));
+
+/* NULL-terminated array of "NAME=VALUE" environment variables.  */
+extern char **__environ;
+extern char **environ;
+
+
+/* Replace the current process, executing PATH with arguments ARGV and
+   environment ENVP.  ARGV and ENVP are terminated by NULL pointers.  */
+extern int __execve __P ((__const char *__path, char *__const __argv[],
+			  char *__const __envp[]));
+extern int execve __P ((__const char *__path, char *__const __argv[],
+			char *__const __envp[]));
+
+#ifdef __USE_GNU
+/* Execute the file FD refers to, overlaying the running program image.
+   ARGV and ENVP are passed to the new program, as for `execve'.  */
+extern int fexecve __P ((int __fd,
+			 char *const __argv[], char *const __envp[]));
+
+#endif
+
+
+/* Execute PATH with arguments ARGV and environment from `environ'.  */
+extern int execv __P ((__const char *__path, char *__const __argv[]));
+
+/* Execute PATH with all arguments after PATH until a NULL pointer,
+   and the argument after that for environment.  */
+extern int execle __P ((__const char *__path, __const char *__arg,...));
+
+/* Execute PATH with all arguments after PATH until
+   a NULL pointer and environment from `environ'.  */
+extern int execl __P ((__const char *__path, __const char *__arg,...));
+
+/* Execute FILE, searching in the `PATH' environment variable if it contains
+   no slashes, with arguments ARGV and environment from `environ'.  */
+extern int execvp __P ((__const char *__file, char *__const __argv[]));
+
+/* Execute FILE, searching in the `PATH' environment variable if
+   it contains no slashes, with all arguments after FILE until a
+   NULL pointer and environment from `environ'.  */
+extern int execlp __P ((__const char *__file, ...));
+
+
+/* Terminate program execution with the low-order 8 bits of STATUS.  */
+extern void _exit __P ((int __status)) __attribute__ ((__noreturn__));
+
+
+/* Get the `_PC_*' symbols for the NAME argument to `pathconf' and `fpathconf';
+   the `_SC_*' symbols for the NAME argument to `sysconf';
+   and the `_CS_*' symbols for the NAME argument to `confstr'.  */
+#include <confname.h>
+
+/* Get file-specific configuration information about PATH.  */
+extern long int __pathconf __P ((__const char *__path, int __name));
+extern long int pathconf __P ((__const char *__path, int __name));
+
+/* Get file-specific configuration about descriptor FD.  */
+extern long int __fpathconf __P ((int __fd, int __name));
+extern long int fpathconf __P ((int __fd, int __name));
+
+/* Get the value of the system variable NAME.  */
+extern long int __sysconf __P ((int __name));
+extern long int sysconf __P ((int __name));
+
+#ifdef	__USE_POSIX2
+/* Get the value of the string-valued system variable NAME.  */
+extern size_t confstr __P ((int __name, char *__buf, size_t __len));
+#endif
+
+
+/* Get the process ID of the calling process.  */
+extern __pid_t __getpid __P ((void));
+extern __pid_t getpid __P ((void));
+
+/* Get the process ID of the calling process's parent.  */
+extern __pid_t __getppid __P ((void));
+extern __pid_t getppid __P ((void));
+
+/* Get the process group ID of the calling process.  */
+extern __pid_t getpgrp __P ((void));
+
+/* Set the process group ID of the process matching PID to PGID.
+   If PID is zero, the current process's process group ID is set.
+   If PGID is zero, the process ID of the process is used.  */
+extern int setpgid __P ((__pid_t __pid, __pid_t __pgid));
+
+/* Get the process group ID of process PID.  */
+extern __pid_t __getpgid __P ((__pid_t __pid));
+#ifdef __USE_GNU
+extern __pid_t getpgid __P ((__pid_t __pid));
+#endif
+
+#ifdef	__USE_BSD
+/* Another name for `setpgid'.  */
+extern int setpgrp __P ((__pid_t __pid, __pid_t __pgrp));
+#endif /* Use BSD.  */
+
+/* Create a new session with the calling process as its leader.
+   The process group IDs of the session and the calling process
+   are set to the process ID of the calling process, which is returned.  */
+extern __pid_t __setsid __P ((void));
+extern __pid_t setsid __P ((void));
+
+/* Get the real user ID of the calling process.  */
+extern __uid_t __getuid __P ((void));
+extern __uid_t getuid __P ((void));
+
+/* Get the effective user ID of the calling process.  */
+extern __uid_t __geteuid __P ((void));
+extern __uid_t geteuid __P ((void));
+
+/* Get the real group ID of the calling process.  */
+extern __gid_t __getgid __P ((void));
+extern __gid_t getgid __P ((void));
+
+/* Get the effective group ID of the calling process.  */
+extern __gid_t __getegid __P ((void));
+extern __gid_t getegid __P ((void));
+
+/* If SIZE is zero, return the number of supplementary groups
+   the calling process is in.  Otherwise, fill in the group IDs
+   of its supplementary groups in LIST and return the number written.  */
+extern int __getgroups __P ((int __size, __gid_t __list[]));
+extern int getgroups __P ((int __size, __gid_t __list[]));
+
+/* Set the user ID of the calling process to UID.
+   If the calling process is the super-user, set the real
+   and effective user IDs, and the saved set-user-ID to UID;
+   if not, the effective user ID is set to UID.  */
+extern int __setuid __P ((__uid_t __uid));
+extern int setuid __P ((__uid_t __uid));
+
+#ifdef	__USE_BSD
+/* Set the real user ID of the calling process to RUID,
+   and the effective user ID of the calling process to EUID.  */
+extern int __setreuid __P ((__uid_t __ruid, __uid_t __euid));
+extern int setreuid __P ((__uid_t __ruid, __uid_t __euid));
+
+/* Set the effective user ID of the calling process to UID.  */
+extern int seteuid __P ((__uid_t __uid));
+#endif /* Use BSD.  */
+
+/* Set the group ID of the calling process to GID.
+   If the calling process is the super-user, set the real
+   and effective group IDs, and the saved set-group-ID to GID;
+   if not, the effective group ID is set to GID.  */
+extern int __setgid __P ((__gid_t __gid));
+extern int setgid __P ((__gid_t __gid));
+
+#ifdef	__USE_BSD
+/* Set the real group ID of the calling process to RGID,
+   and the effective group ID of the calling process to EGID.  */
+extern int __setregid __P ((__gid_t __rgid, __gid_t __egid));
+extern int setregid __P ((__gid_t __rgid, __gid_t __egid));
+
+/* Set the effective group ID of the calling process to GID.  */
+extern int setegid __P ((__gid_t __gid));
+#endif /* Use BSD.  */
+
+
+/* Clone the calling process, creating an exact copy.
+   Return -1 for errors, 0 to the new process,
+   and the process ID of the new process to the old process.  */
+extern __pid_t __fork __P ((void));
+extern __pid_t fork __P ((void));
+
+#ifdef	__USE_BSD
+/* Clone the calling process, but without copying the whole address space.
+   The the calling process is suspended until the the new process exits or is
+   replaced by a call to `execve'.  Return -1 for errors, 0 to the new process,
+   and the process ID of the new process to the old process.  */
+extern __pid_t __vfork __P ((void));
+extern __pid_t vfork __P ((void));
+#endif /* Use BSD. */
+
+
+/* Return the pathname of the terminal FD is open on, or NULL on errors.
+   The returned storage is good only until the next call to this function.  */
+extern char *ttyname __P ((int __fd));
+
+/* Return 1 if FD is a valid descriptor associated
+   with a terminal, zero if not.  */
+extern int __isatty __P ((int __fd));
+extern int isatty __P ((int __fd));
+
+
+/* Make a link to FROM named TO.  */
+extern int __link __P ((__const char *__from, __const char *__to));
+extern int link __P ((__const char *__from, __const char *__to));
+
+#ifdef	__USE_BSD
+/* Make a symbolic link to FROM named TO.  */
+extern int __symlink __P ((__const char *__from, __const char *__to));
+extern int symlink __P ((__const char *__from, __const char *__to));
+
+/* Read the contents of the symbolic link PATH into no more than
+   LEN bytes of BUF.  The contents are not null-terminated.
+   Returns the number of characters read, or -1 for errors.  */
+extern int __readlink __P ((__const char *__path, char *__buf, size_t __len));
+extern int readlink __P ((__const char *__path, char *__buf, size_t __len));
+#endif /* Use BSD.  */
+
+/* Remove the link NAME.  */
+extern int __unlink __P ((__const char *__name));
+extern int unlink __P ((__const char *__name));
+
+/* Remove the directory PATH.  */
+extern int __rmdir __P ((__const char *__path));
+extern int rmdir __P ((__const char *__path));
+
+
+/* Return the foreground process group ID of FD.  */
+extern __pid_t tcgetpgrp __P ((int __fd));
+
+/* Set the foreground process group ID of FD set PGRP_ID.  */
+extern int tcsetpgrp __P ((int __fd, __pid_t __pgrp_id));
+
+
+/* Return the login name of the user.  */
+extern char *getlogin __P ((void));
+
+#ifdef	__USE_BSD
+/* Set the login name returned by `getlogin'.  */
+extern int setlogin __P ((__const char *__name));
+#endif
+
+
+#ifdef	__USE_POSIX2
+/* Process the arguments in ARGV (ARGC of them, minus
+   the program name) for options given in OPTS.
+
+   If `opterr' is zero, no messages are generated
+   for invalid options; it defaults to 1.
+   `optind' is the current index into ARGV.
+   `optarg' is the argument corresponding to the current option.
+   Return the option character from OPTS just read.
+   Return -1 when there are no more options.
+   For unrecognized options, or options missing arguments,
+   `optopt' is set to the option letter, and '?' is returned.
+
+   The OPTS string is a list of characters which are recognized option
+   letters, optionally followed by colons, specifying that that letter
+   takes an argument, to be placed in `optarg'.
+
+   If a letter in OPTS is followed by two colons, its argument is optional.
+   This behavior is specific to the GNU `getopt'.
+
+   The argument `--' causes premature termination of argument scanning,
+   explicitly telling `getopt' that there are no more options.
+
+   If OPTS begins with `--', then non-option arguments
+   are treated as arguments to the option '\0'.
+   This behavior is specific to the GNU `getopt'.  */
+extern int getopt __P ((int __argc, char *__const * __argv,
+			__const char *__opts));
+extern int opterr;
+extern int optind;
+extern int optopt;
+extern char *optarg;
+#endif
+
+
+#ifdef	__USE_BSD
+
+/* Put the name of the current host in no more than LEN bytes of NAME.
+   The result is null-terminated if LEN is large enough for the full
+   name and the terminator.  */
+extern int __gethostname __P ((char *__name, size_t __len));
+extern int gethostname __P ((char *__name, size_t __len));
+
+/* Set the name of the current host to NAME, which is LEN bytes long.
+   This call is restricted to the super-user.  */
+extern int sethostname __P ((__const char *__name, size_t __len));
+
+/* Return the current machine's Internet number.  */
+extern long int gethostid __P ((void));
+
+/* Set the current machine's Internet number to ID.
+   This call is restricted to the super-user.  */
+extern int sethostid __P ((long int __id));
+
+
+/* Return the number of bytes in a page.  This is the system's page size,
+   which is not necessarily the same as the hardware page size.  */
+extern size_t __getpagesize __P ((void));
+extern size_t getpagesize __P ((void));
+
+
+/* Return the maximum number of file descriptors
+   the current process could possibly have.  */
+extern int __getdtablesize __P ((void));
+extern int getdtablesize __P ((void));
+
+
+/* Truncate FILE to LENGTH bytes.  */
+extern int truncate __P ((__const char *__file, __off_t __length));
+
+/* Truncate the file FD is open on to LENGTH bytes.  */
+extern int ftruncate __P ((int __fd, __off_t __length));
+
+
+/* Make all changes done to FD actually appear on disk.  */
+extern int fsync __P ((int __fd));
+
+/* Make all changes done to all files actually appear on disk.  */
+extern int sync __P ((void));
+
+
+/* Revoke access permissions to all processes currently communicating
+   with the control terminal, and then send a SIGHUP signal to the process
+   group of the control terminal.  */
+extern int vhangup __P ((void));
+
+
+/* Turn accounting on if NAME is an existing file.  The system will then write
+   a record for each process as it terminates, to this file.  If NAME is NULL,
+   turn accounting off.  This call is restricted to the super-user.  */
+extern int acct __P ((__const char *__name));
+
+/* Make PATH be the root directory (the starting point for absolute paths).
+   This call is restricted to the super-user.  */
+extern int chroot __P ((__const char *__path));
+
+/* Make the block special device PATH available to the system for swapping.
+   This call is restricted to the super-user.  */
+extern int swapon __P ((__const char *__path));
+
+/* Reboot or halt the system.  */
+extern int reboot __P ((int __howto));
+
+
+/* Successive calls return the shells listed in `/etc/shells'.  */
+extern char *getusershell __P ((void));
+extern void endusershell __P ((void)); /* Discard cached info.  */
+extern void setusershell __P ((void)); /* Rewind and re-read the file.  */
+
+
+/* Prompt with PROMPT and read a string from the terminal without echoing.
+   Uses /dev/tty if possible; otherwise stderr and stdin.  */
+extern char *getpass __P ((const char *__prompt));
+
+/* Put the program in the background, and dissociate from the controlling
+   terminal.  If NOCHDIR is zero, do `chdir ("/")'.  If NOCLOSE is zero,
+   redirects stdin, stdout, and stderr to /dev/null.  */
+extern int daemon __P ((int __nochdir, int __noclose));
+
+#endif /* Use BSD.  */
+
+
+#ifdef __USE_MISC
+
+/* Generate a unique temporary file name from TEMPLATE.
+   The last six characters of TEMPLATE must be "XXXXXX";
+   they are replaced with a string that makes the file name unique.
+   Returns TEMPLATE, or a null pointer if it cannot get a unique file name.  */
+extern char *mktemp __P ((char *__template));
+
+/* Generate a unique temporary file name from TEMPLATE.
+   The last six characters of TEMPLATE must be "XXXXXX";
+   they are replaced with a string that makes the filename unique.
+   Returns a file descriptor open on the file for reading and writing,
+   or -1 if it cannot create a uniquely-named file.  */
+extern int mkstemp __P ((char *__template));
+
+
+/* Invoke `system call' number SYSNO, passing it the remaining arguments.
+   This is completely system-dependent, and not often useful.
+
+   In Unix, `syscall' sets `errno' for all errors and most calls return -1
+   for errors; in many systems you cannot pass arguments or get return
+   values for all system calls (`pipe', `fork', and `getppid' typically
+   among them).
+
+   In Mach, all system calls take normal arguments and always return an
+   error code (zero for success).  */
+extern int syscall __P ((int __sysno, ...));
+
+#endif	/* Use misc.  */
+
+
+#if defined (__USE_MISC) && !defined (F_LOCK)
+/* NOTE: These declarations also appear in <fcntl.h>; be sure to keep both
+   files consistent.  Some systems have them there and some here, and some
+   software depends on the macros being defined without including both.  */
+
+/* `lockf' is a simpler interface to the locking facilities of `fcntl'.
+   LEN is always relative to the current file position.
+   The CMD argument is one of the following.  */
+
+#define F_ULOCK 0       /* Unlock a previously locked region.  */
+#define F_LOCK  1       /* Lock a region for exclusive use.  */ 
+#define F_TLOCK 2       /* Test and lock a region for exclusive use.  */
+#define F_TEST  3       /* Test a region for other processes locks.  */
+
+extern int lockf __P ((int __fd, int __cmd, __off_t __len));
+#endif /* Use misc and F_LOCK not already defined.  */
+
+
+#ifdef __USE_GNU
+
+/* Evaluate EXPRESSION, and repeat as long as it returns -1 with `errno'
+   set to EINTR.  */
+
+#define TEMP_FAILURE_RETRY(expression) \
+  ({ long int __result;							      \
+       do __result = (long int) (expression);				      \
+       while (__result == -1L && errno == EINTR);			      \
+       __result; })
+          
+#endif
+
+__END_DECLS
+
+#endif /* unistd.h  */