path: root/include/unistd.h

/* Copyright (C) 1991-2002,2003,2004,2005,2006 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 Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 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 ISO/IEC 9945-1 as of December 2001.  */
#define	_POSIX_VERSION	200112L

/* These are not #ifdef __USE_POSIX2 because they are
   in the theoretically application-owned namespace.  */

/* The utilities on GNU systems also correspond to this version.  */
#define _POSIX2_VERSION	200112L

/* If defined, the implementation supports the
   C Language Bindings Option.  */
#define	_POSIX2_C_BIND	200112L

/* If defined, the implementation supports the
   C Language Development Utilities Option.  */
#define	_POSIX2_C_DEV	200112L

/* If defined, the implementation supports the
   Software Development Utilities Option.  */
#define	_POSIX2_SW_DEV	200112L

/* If defined, the implementation supports the
   creation of locales with the localedef utility.  */
#define _POSIX2_LOCALEDEF       200112L

/* X/Open version number to which the library conforms.  It is selectable.  */
#ifdef __USE_UNIX98
# define _XOPEN_VERSION	500
#else
# define _XOPEN_VERSION	4
#endif

/* Commands and utilities from XPG4 are available.  */
#define _XOPEN_XCU_VERSION	4

/* We are compatible with the old published standards as well.  */
#define _XOPEN_XPG2	1
#define _XOPEN_XPG3	1
#define _XOPEN_XPG4	1

/* The X/Open Unix extensions are available.  */
#define _XOPEN_UNIX	1

/* Encryption is present.  */
#define	_XOPEN_CRYPT	1

/* The enhanced internationalization capabilities according to XPG4.2
   are present.  */
#define	_XOPEN_ENH_I18N	1

/* The legacy interfaces are also available.  */
#define _XOPEN_LEGACY	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.
   _POSIX_REALTIME_SIGNALS	Real-time, queued signals are supported.
   _POSIX_PRIORITY_SCHEDULING	Priority scheduling is supported.
   _POSIX_TIMERS		POSIX.4 clocks and timers are supported.
   _POSIX_ASYNCHRONOUS_IO	Asynchronous I/O is supported.
   _POSIX_PRIORITIZED_IO	Prioritized asynchronous I/O is supported.
   _POSIX_SYNCHRONIZED_IO	Synchronizing file data is supported.
   _POSIX_FSYNC			The fsync function is present.
   _POSIX_MAPPED_FILES		Mapping of files to memory is supported.
   _POSIX_MEMLOCK		Locking of all memory is supported.
   _POSIX_MEMLOCK_RANGE		Locking of ranges of memory is supported.
   _POSIX_MEMORY_PROTECTION	Setting of memory protections is supported.
   _POSIX_MESSAGE_PASSING	POSIX.4 message queues are supported.
   _POSIX_SEMAPHORES		POSIX.4 counting semaphores are supported.
   _POSIX_SHARED_MEMORY_OBJECTS	POSIX.4 shared memory objects are supported.
   _POSIX_THREADS		POSIX.1c pthreads are supported.
   _POSIX_THREAD_ATTR_STACKADDR	Thread stack address attribute option supported.
   _POSIX_THREAD_ATTR_STACKSIZE	Thread stack size attribute option supported.
   _POSIX_THREAD_SAFE_FUNCTIONS	Thread-safe functions are supported.
   _POSIX_THREAD_PRIORITY_SCHEDULING
				POSIX.1c thread execution scheduling supported.
   _POSIX_THREAD_PRIO_INHERIT	Thread priority inheritance option supported.
   _POSIX_THREAD_PRIO_PROTECT	Thread priority protection option supported.
   _POSIX_THREAD_PROCESS_SHARED	Process-shared synchronization supported.
   _POSIX_PII			Protocol-independent interfaces are supported.
   _POSIX_PII_XTI		XTI protocol-indep. interfaces are supported.
   _POSIX_PII_SOCKET		Socket protocol-indep. interfaces are supported.
   _POSIX_PII_INTERNET		Internet family of protocols supported.
   _POSIX_PII_INTERNET_STREAM	Connection-mode Internet protocol supported.
   _POSIX_PII_INTERNET_DGRAM	Connectionless Internet protocol supported.
   _POSIX_PII_OSI		ISO/OSI family of protocols supported.
   _POSIX_PII_OSI_COTS		Connection-mode ISO/OSI service supported.
   _POSIX_PII_OSI_CLTS		Connectionless ISO/OSI service supported.
   _POSIX_POLL			Implementation supports `poll' function.
   _POSIX_SELECT		Implementation supports `select' and `pselect'.

   _XOPEN_REALTIME		X/Open realtime support is available.
   _XOPEN_REALTIME_THREADS	X/Open realtime thread support is available.
   _XOPEN_SHM			Shared memory interface according to XPG4.2.

   _XBS5_ILP32_OFF32		Implementation provides environment with 32-bit
				int, long, pointer, and off_t types.
   _XBS5_ILP32_OFFBIG		Implementation provides environment with 32-bit
				int, long, and pointer and off_t with at least
				64 bits.
   _XBS5_LP64_OFF64		Implementation provides environment with 32-bit
				int, and 64-bit long, pointer, and off_t types.
   _XBS5_LPBIG_OFFBIG		Implementation provides environment with at
				least 32 bits int and long, pointer, and off_t
				with at least 64 bits.

   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.
   _POSIX_SYNC_IO		Synchronous I/O may be performed.
   _POSIX_ASYNC_IO		Asynchronous I/O may be performed.
   _POSIX_PRIO_IO		Prioritized Asynchronous I/O may be performed.

   Support for the Large File Support interface is not generally available.
   If it is available the following constants are defined to one.
   _LFS64_LARGEFILE		Low-level I/O supports large files.
   _LFS64_STDIO			Standard I/O supports large files.
   */

#include <bits/posix_opt.h>

/* Get the environment definitions from Unix98.  */
#ifdef __USE_UNIX98
# include <bits/environments.h>
#endif

/* 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 <bits/types.h>

#ifndef	__ssize_t_defined
typedef __ssize_t ssize_t;
# define __ssize_t_defined
#endif

#define	__need_size_t
#define __need_NULL
#include <stddef.h>

#if defined __USE_XOPEN || defined __USE_XOPEN2K
/* The Single Unix specification says that some more types are
   available here.  */
# ifndef __gid_t_defined
typedef __gid_t gid_t;
#  define __gid_t_defined
# endif

# ifndef __uid_t_defined
typedef __uid_t uid_t;
#  define __uid_t_defined
# endif

# ifndef __off_t_defined
#  ifndef __USE_FILE_OFFSET64
typedef __off_t off_t;
#  else
typedef __off64_t off_t;
#  endif
#  define __off_t_defined
# endif
# if defined __USE_LARGEFILE64 && !defined __off64_t_defined
typedef __off64_t off64_t;
#  define __off64_t_defined
# endif

# ifndef __useconds_t_defined
typedef __useconds_t useconds_t;
#  define __useconds_t_defined
# endif

# ifndef __pid_t_defined
typedef __pid_t pid_t;
#  define __pid_t_defined
# endif
#endif	/* X/Open */

#if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
# ifndef __intptr_t_defined
typedef __intptr_t intptr_t;
#  define __intptr_t_defined
# endif
#endif

#if defined __USE_BSD || defined __USE_XOPEN
# ifndef __socklen_t_defined
typedef __socklen_t socklen_t;
#  define __socklen_t_defined
# endif
#endif

/* 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 using the real UID and real GID.  */
extern int access (__const char *__name, int __type) __THROW __nonnull ((1));

#if 0 /*def __USE_GNU*/
/* Test for access to NAME using the effective UID and GID
   (as normal file operations use).  */
extern int euidaccess (__const char *__name, int __type)
     __THROW __nonnull ((1));

/* An alias for `euidaccess', used by some other systems.  */
extern int eaccess (__const char *__name, int __type)
     __THROW __nonnull ((1));
#endif

#ifdef __USE_ATFILE
/* Test for access to FILE relative to the directory FD is open on.
   If AT_EACCESS is set in FLAG, then use effective IDs like `eaccess',
   otherwise use real IDs like `access'.  */
extern int faccessat (int __fd, __const char *__file, int __type, int __flag)
     __THROW __nonnull ((2)) __wur;
#endif /* Use GNU.  */


/* 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

#if defined __USE_BSD && !defined L_SET
/* Old BSD names for the same constants; just for compatibility.  */
# define L_SET		SEEK_SET
# define L_INCR		SEEK_CUR
# define L_XTND		SEEK_END
#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.  */
#ifndef __USE_FILE_OFFSET64
extern __off_t lseek (int __fd, __off_t __offset, int __whence) __THROW;
libc_hidden_proto(lseek)
#else
# ifdef __REDIRECT_NTH
extern __off64_t __REDIRECT_NTH (lseek,
				 (int __fd, __off64_t __offset, int __whence),
				 lseek64);
# else
#  define lseek lseek64
# endif
#endif
#ifdef __USE_LARGEFILE64
extern __off64_t lseek64 (int __fd, __off64_t __offset, int __whence)
     __THROW;
libc_hidden_proto(lseek64)
#endif

/* Close the file descriptor FD.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
extern int close (int __fd);
libc_hidden_proto(close)

/* Read NBYTES into BUF from FD.  Return the
   number read, -1 for errors or 0 for EOF.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
extern ssize_t read (int __fd, void *__buf, size_t __nbytes) __wur;
libc_hidden_proto(read)

/* Write N bytes of BUF to FD.  Return the number written, or -1.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
extern ssize_t write (int __fd, __const void *__buf, size_t __n) __wur;
libc_hidden_proto(write)

#ifdef __USE_UNIX98
# ifndef __USE_FILE_OFFSET64
/* Read NBYTES into BUF from FD at the given position OFFSET without
   changing the file pointer.  Return the number read, -1 for errors
   or 0 for EOF.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
extern ssize_t pread (int __fd, void *__buf, size_t __nbytes,
		      __off_t __offset) __wur;

/* Write N bytes of BUF to FD at the given position OFFSET without
   changing the file pointer.  Return the number written, or -1.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
extern ssize_t pwrite (int __fd, __const void *__buf, size_t __n,
		       __off_t __offset) __wur;
# else
#  ifdef __REDIRECT
extern ssize_t __REDIRECT (pread, (int __fd, void *__buf, size_t __nbytes,
				   __off64_t __offset),
			   pread64) __wur;
extern ssize_t __REDIRECT (pwrite, (int __fd, __const void *__buf,
				    size_t __nbytes, __off64_t __offset),
			   pwrite64) __wur;
#  else
#   define pread pread64
#   define pwrite pwrite64
#  endif
# endif

# ifdef __USE_LARGEFILE64
/* Read NBYTES into BUF from FD at the given position OFFSET without
   changing the file pointer.  Return the number read, -1 for errors
   or 0 for EOF.  */
extern ssize_t pread64 (int __fd, void *__buf, size_t __nbytes,
			__off64_t __offset) __wur;
/* Write N bytes of BUF to FD at the given position OFFSET without
   changing the file pointer.  Return the number written, or -1.  */
extern ssize_t pwrite64 (int __fd, __const void *__buf, size_t __n,
			 __off64_t __offset) __wur;
# endif
#endif

/* Create a one-way communication channel (pipe).
   If successful, 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 (int __pipedes[2]) __THROW __wur;
libc_hidden_proto(pipe)

/* 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 (unsigned int __seconds) __THROW;
libc_hidden_proto(alarm)

/* 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.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
extern unsigned int sleep (unsigned int __seconds);
libc_hidden_proto(sleep)

#if (defined __USE_BSD || defined __USE_XOPEN_EXTENDED) \
	&& defined __UCLIBC_SUSV3_LEGACY__
/* Set an alarm to go off (generating a SIGALRM signal) in VALUE
   microseconds.  If INTERVAL is nonzero, when the alarm goes off, the
   timer is reset to go off every INTERVAL microseconds thereafter.
   Returns the number of microseconds remaining before the alarm.  */
extern __useconds_t ualarm (__useconds_t __value, __useconds_t __interval)
     __THROW;

/* Sleep USECONDS microseconds, or until a signal arrives that is not blocked
   or ignored.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
extern int usleep (__useconds_t __useconds);
#endif


/* Suspend the process until a signal arrives.
   This always returns -1 and sets `errno' to EINTR.

   This function is a cancellation point and therefore not marked with
   __THROW.  */
extern int pause (void);


/* Change the owner and group of FILE.  */
extern int chown (__const char *__file, __uid_t __owner, __gid_t __group)
     __THROW __nonnull ((1)) __wur;
libc_hidden_proto(chown)

#if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
/* Change the owner and group of the file that FD is open on.  */
extern int fchown (int __fd, __uid_t __owner, __gid_t __group) __THROW __wur;


/* Change owner and group of FILE, if it is a symbolic
   link the ownership of the symbolic link is changed.  */
extern int lchown (__const char *__file, __uid_t __owner, __gid_t __group)
     __THROW __nonnull ((1)) __wur;

#endif /* Use BSD || X/Open Unix.  */

#ifdef __USE_ATFILE
/* Change the owner and group of FILE relative to the directory FD is open
   on.  */
extern int fchownat (int __fd, __const char *__file, __uid_t __owner,
		     __gid_t __group, int __flag)
     __THROW __nonnull ((2)) __wur;
#endif /* Use GNU.  */

/* Change the process's working directory to PATH.  */
extern int chdir (__const char *__path) __THROW __nonnull ((1)) __wur;
libc_hidden_proto(chdir)

#if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
/* Change the process's working directory to the one FD is open on.  */
extern int fchdir (int __fd) __THROW __wur;
libc_hidden_proto(fchdir)
#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 (char *__buf, size_t __size) __THROW __wur;
libc_hidden_proto(getcwd)

#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 (void) __THROW;
#endif

#if 0 /*defined __USE_BSD || defined __USE_XOPEN_EXTENDED*/
/* 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 (char *__buf)
     __THROW __nonnull ((1)) __attribute_deprecated__ __wur;
#endif


/* Duplicate FD, returning a new file descriptor on the same file.  */
extern int dup (int __fd) __THROW __wur;

/* Duplicate FD to FD2, closing FD2 and making it open on the same file.  */
extern int dup2 (int __fd, int __fd2) __THROW;
libc_hidden_proto(dup2)

/* NULL-terminated array of "NAME=VALUE" environment variables.  */
extern char **__environ;
#ifdef __USE_GNU
extern char **environ;
#endif


/* Replace the current process, executing PATH with arguments ARGV and
   environment ENVP.  ARGV and ENVP are terminated by NULL pointers.  */
extern int execve (__const char *__path, char *__const __argv[],
		   char *__const __envp[]) __THROW __nonnull ((1));
libc_hidden_proto(execve)

#if 0 /*def __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 (int __fd, char *__const __argv[], char *__const __envp[])
     __THROW;
#endif


/* Execute PATH with arguments ARGV and environment from `environ'.  */
extern int execv (__const char *__path, char *__const __argv[])
     __THROW __nonnull ((1));
libc_hidden_proto(execv)

/* Execute PATH with all arguments after PATH until a NULL pointer,
   and the argument after that for environment.  */
extern int execle (__const char *__path, __const char *__arg, ...)
     __THROW __nonnull ((1));
libc_hidden_proto(execle)

/* Execute PATH with all arguments after PATH until
   a NULL pointer and environment from `environ'.  */
extern int execl (__const char *__path, __const char *__arg, ...)
     __THROW __nonnull ((1));
libc_hidden_proto(execl)

/* Execute FILE, searching in the `PATH' environment variable if it contains
   no slashes, with arguments ARGV and environment from `environ'.  */
extern int execvp (__const char *__file, char *__const __argv[])
     __THROW __nonnull ((1));
libc_hidden_proto(execvp)

/* 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 (__const char *__file, __const char *__arg, ...)
     __THROW __nonnull ((1));
libc_hidden_proto(execlp)


#if defined __USE_MISC || defined __USE_XOPEN
/* Add INC to priority of the current process.  */
extern int nice (int __inc) __THROW __wur;
#endif


/* Terminate program execution with the low-order 8 bits of STATUS.  */
extern void _exit (int __status) __attribute__ ((__noreturn__));
libc_hidden_proto(_exit)


/* 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 <bits/confname.h>

/* Get file-specific configuration information about PATH.  */
extern long int pathconf (__const char *__path, int __name)
     __THROW __nonnull ((1));

/* Get file-specific configuration about descriptor FD.  */
extern long int fpathconf (int __fd, int __name) __THROW;

/* Get the value of the system variable NAME.  */
extern long int sysconf (int __name) __THROW;
libc_hidden_proto(sysconf)

#ifdef	__USE_POSIX2
/* Get the value of the string-valued system variable NAME.  */
extern size_t confstr (int __name, char *__buf, size_t __len) __THROW;
#endif


/* Get the process ID of the calling process.  */
extern __pid_t getpid (void) __THROW;
libc_hidden_proto(getpid)

/* Get the process ID of the calling process's parent.  */
extern __pid_t getppid (void