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		  */ __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. */ /* 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. */ /* If defined, the implementation supports the C Language Bindings Option. */ /* If defined, the implementation supports the C Language Development Utilities Option. */ /* If defined, the implementation supports the Software Development Utilities Option. */ /* If defined, the implementation supports the creation of locales with the localedef utility. */ /* X/Open version number to which the library conforms. It is selectable. */ /* Commands and utilities from XPG4 are available. */ /* We are compatible with the old published standards as well. */ /* The X/Open Unix extensions are available. */ /* Encryption is present. */ /* The enhanced internationalization capabilities according to XPG4.2 are present. */ /* The legacy interfaces are also available. */ /* 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. */ /* Get the environment definitions from Unix98. */ /* Standard file descriptors. */ /* All functions that are not declared anywhere else. */ typedef __ssize_t ssize_t; /* The Single Unix specification says that some more types are available here. */ typedef __gid_t gid_t; typedef __uid_t uid_t; typedef __off_t off_t; typedef __off64_t off_t; typedef __off64_t off64_t; typedef __useconds_t useconds_t; typedef __pid_t pid_t; typedef __intptr_t intptr_t; typedef __socklen_t socklen_t; /* Values for the second argument to access. These may be OR'd together. */ /* Test for access to NAME using the real UID and real GID. */ extern int access (__const char *__name, int __type) __THROW __nonnull ((1)); /* 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)); /* 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; /* Values for the WHENCE argument to lseek. */ /* Old BSD names for the same constants; just for compatibility. */ /* 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 (int __fd, __off_t __offset, int __whence) __THROW; extern __off64_t __REDIRECT_NTH (lseek, 				 (int __fd, __off64_t __offset, int __whence), 				 lseek64); extern __off64_t lseek64 (int __fd, __off64_t __offset, int __whence) __THROW; /* Close the file descriptor FD. This function is a cancellation point and therefore not marked with __THROW. */ extern int close (int __fd); /* 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; /* 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; /* 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; 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; /* 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; /* 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; /* 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; /* 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); /* 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); /* 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; /* 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; /* 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; /* Change the process's working directory to PATH. */ extern int chdir (__const char *__path) __THROW __nonnull ((1)) __wur; /* Change the process's working directory to the one FD is open on. */ extern int fchdir (int __fd) __THROW __wur; /* 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; /* 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; /* 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; /* 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; /* 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 (__const char *__path, char *__const __argv[], 		  char *__const __envp[]) __THROW __nonnull ((1)); /* 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; /* Execute PATH with arguments ARGV and environment from `environ'. */ extern int execv (__const char *__path, char *__const __argv[]) __THROW __nonnull ((1)); /* 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)); /* 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)); /* 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)); /* 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)); /* Add INC to priority of the current process. */ extern int nice (int __inc) __THROW __wur; /* Terminate program execution with the low-order 8 bits of STATUS. */ extern void _exit (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'. */ /* 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; /* Get the value of the string-valued system variable NAME. */ extern size_t confstr (int __name, char *__buf, size_t __len) __THROW; /* Get the process ID of the calling process. */ extern __pid_t getpid (void) __THROW; /* Get the process ID of the calling process's parent. */ extern __pid_t getppid (void) __THROW; /* Get the process group ID of the calling process. This function is different on old BSD. */ extern __pid_t getpgrp (void) __THROW; extern __pid_t __REDIRECT_NTH (getpgrp, (__pid_t __pid), __getpgid); /* Get the process group ID of process PID. */ extern __pid_t __getpgid (__pid_t __pid) __THROW; extern __pid_t getpgid (__pid_t __pid) __THROW; /* 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 (__pid_t __pid, __pid_t __pgid) __THROW; /* Both System V and BSD have `setpgrp' functions, but with different calling conventions. The BSD function is the same as POSIX.1 `setpgid' (above). The System V function takes no arguments and puts the calling process in its on group like `setpgid (0, 0)'. New programs should always use `setpgid' instead. The default in GNU is to provide the System V function. The BSD function is available under -D_BSD_SOURCE. */ /* Set the process group ID of the calling process to its own PID. This is exactly the same as `setpgid (0, 0)'. */ extern int setpgrp (void) __THROW; /* Another name for `setpgid' (above). */ extern int __REDIRECT_NTH (setpgrp, (__pid_t __pid, __pid_t __pgrp), setpgid); /* 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 (void) __THROW; /* Return the session ID of the given process. */ extern __pid_t getsid (__pid_t __pid) __THROW; /* Get the real user ID of the calling process. */ extern __uid_t getuid (void) __THROW; /* Get the effective user ID of the calling process. */ extern __uid_t geteuid (void) __THROW; /* Get the real group ID of the calling process. */ extern __gid_t getgid (void) __THROW; /* Get the effective group ID of the calling process. */ extern __gid_t getegid (void) __THROW; /* 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 (int __size, __gid_t __list[]) __THROW __wur; /* Return nonzero iff the calling process is in group GID. */ extern int group_member (__gid_t __gid) __THROW; /* 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 (__uid_t __uid) __THROW; /* 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 (__uid_t __ruid, __uid_t __euid) __THROW; /* Set the effective user ID of the calling process to UID. */ extern int seteuid (__uid_t __uid) __THROW; /* 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 (__gid_t __gid) __THROW; /* 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 (__gid_t __rgid, __gid_t __egid) __THROW; /* Set the effective group ID of the calling process to GID. */ extern int setegid (__gid_t __gid) __THROW; /* Fetch the real user ID, effective user ID, and saved-set user ID, of the calling process. */ extern int getresuid (__uid_t *__ruid, __uid_t *__euid, __uid_t *__suid) __THROW; /* Fetch the real group ID, effective group ID, and saved-set group ID, of the calling process. */ extern int getresgid (__gid_t *__rgid, __gid_t *__egid, __gid_t *__sgid) __THROW; /* Set the real user ID, effective user ID, and saved-set user ID, of the calling process to RUID, EUID, and SUID, respectively. */ extern int setresuid (__uid_t __ruid, __uid_t __euid, __uid_t __suid) __THROW; /* Set the real group ID, effective group ID, and saved-set group ID, of the calling process to RGID, EGID, and SGID, respectively. */ extern int setresgid (__gid_t __rgid, __gid_t __egid, __gid_t __sgid) __THROW; /* 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 (void) __THROW; /* Clone the calling process, but without copying the whole address space. The calling process is suspended until 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 (void) __THROW; /* 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 (int __fd) __THROW; /* Store at most BUFLEN characters of the pathname of the terminal FD is   open on in BUF. Return 0 on success, otherwise an error number. */ extern int ttyname_r (int __fd, char *__buf, size_t __buflen) __THROW __nonnull ((2)) __wur; /* Return 1 if FD is a valid descriptor associated with a terminal, zero if not. */ extern int isatty (int __fd) __THROW; || (defined __USE_XOPEN_EXTENDED && !defined __USE_UNIX98) /* Return the index into the active-logins file (utmp) for the controlling terminal. */ extern int ttyslot (void) __THROW; /* Make a link to FROM named TO. */ extern int link (__const char *__from, __const char *__to) __THROW __nonnull ((1, 2)) __wur; /* Like link but relative paths in TO and FROM are interpreted relative to FROMFD and TOFD respectively. */ extern int linkat (int __fromfd, __const char *__from, int __tofd, 		  __const char *__to, int __flags) __THROW __nonnull ((2, 4)) __wur; /* Make a symbolic link to FROM named TO. */ extern int symlink (__const char *__from, __const char *__to) __THROW __nonnull ((1, 2)) __wur; /* 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 ssize_t readlink (__const char *__restrict __path, 			 char *__restrict __buf, size_t __len) __THROW __nonnull ((1, 2)) __wur; /* Like symlink but a relative path in TO is interpreted relative to TOFD. */ extern int symlinkat (__const char *__from, int __tofd, 		     __const char *__to) __THROW __nonnull ((1, 3)) __wur; /* Like readlink but a relative PATH is interpreted relative to FD. */ extern ssize_t readlinkat (int __fd, __const char *__restrict __path, 			  char *__restrict __buf, size_t __len) __THROW __nonnull ((2, 3)) __wur; /* Remove the link NAME. */ extern int unlink (__const char *__name) __THROW __nonnull ((1)); /* Remove the link NAME relative to FD. */ extern int unlinkat (int __fd, __const char *__name, int __flag) __THROW __nonnull ((2)); /* Remove the directory PATH. */ extern int rmdir (__const char *__path) __THROW __nonnull ((1)); /* Return the foreground process group ID of FD. */ extern __pid_t tcgetpgrp (int __fd) __THROW; /* Set the foreground process group ID of FD set PGRP_ID. */ extern int tcsetpgrp (int __fd, __pid_t __pgrp_id) __THROW; /* Return the login name of the user. This function is a possible cancellation points and therefore not marked with __THROW. */ extern char *getlogin (void); /* Return at most NAME_LEN characters of the login name of the user in NAME. If it cannot be determined or some other error occurred, return the error code. Otherwise return 0. This function is a possible cancellation points and therefore not marked with __THROW. */ extern int getlogin_r (char *__name, size_t __name_len) __nonnull ((1)); /* Set the login name returned by `getlogin'. */ extern int setlogin (__const char *__name) __THROW __nonnull ((1)); /* Get definitions and prototypes for functions to process the arguments in ARGV (ARGC of them, minus the program name) for options given in OPTS. */ /* 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 (char *__name, size_t __len) __THROW __nonnull ((1)); /* 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 (__const char *__name, size_t __len) __THROW __nonnull ((1)) __wur; /* Set the current machine's Internet number to ID. This call is restricted to the super-user. */ extern int sethostid (long int __id) __THROW __wur; /* Get and set the NIS (aka YP) domain name, if any. Called just like `gethostname' and `sethostname'. The NIS domain name is usually the empty string when not using NIS. */ extern int getdomainname (char *__name, size_t __len) __THROW __nonnull ((1)) __wur; extern int setdomainname (__const char *__name, size_t __len) __THROW __nonnull ((1)) __wur; /* 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 (void) __THROW; /* Revoke the access of all descriptors currently open on FILE. */ extern int revoke (__const char *__file) __THROW __nonnull ((1)) __wur; /* Enable statistical profiling, writing samples of the PC into at most SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling is enabled, the system examines the user PC and increments SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536]. If SCALE is zero, disable profiling. Returns zero on success, -1 on error. */ extern int profil (unsigned short int *__sample_buffer, size_t __size, 		  size_t __offset, unsigned int __scale) __THROW __nonnull ((1)); /* 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 (__const char *__name) __THROW; /* Successive calls return the shells listed in `/etc/shells'. */ extern char *getusershell (void) __THROW; extern void endusershell (void) __THROW; /* Discard cached info. */ extern void setusershell (void) __THROW; /* Rewind and re-read the file. */ /* 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 (int __nochdir, int __noclose) __THROW __wur; /* Make PATH be the root directory (the starting point for absolute paths). This call is restricted to the super-user. */ extern int chroot (__const char *__path) __THROW __nonnull ((1)) __wur; /* Prompt with PROMPT and read a string from the terminal without echoing. Uses /dev/tty if possible; otherwise stderr and stdin. */ extern char *getpass (__const char *__prompt) __nonnull ((1)); /* Make all changes done to FD actually appear on disk. This function is a cancellation point and therefore not marked with __THROW. */ extern int fsync (int __fd); /* Return identifier for the current host. */ extern long int gethostid (void); /* Make all changes done to all files actually appear on disk. */ extern void sync (void) __THROW; /* 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 int getpagesize (void) __THROW __attribute__ ((__const__)); /* Return the maximum number of file descriptors the current process could possibly have. */ extern int getdtablesize (void) __THROW; /* Truncate FILE to LENGTH bytes. */ extern int truncate (__const char *__file, __off_t __length) __THROW __nonnull ((1)) __wur; extern int __REDIRECT_NTH (truncate, 			  (__const char *__file, __off64_t __length), 			   truncate64) __nonnull ((1)) __wur; extern int truncate64 (__const char *__file, __off64_t __length) __THROW __nonnull ((1)) __wur; /* Truncate the file FD is open on to LENGTH bytes. */ extern int ftruncate (int __fd, __off_t __length) __THROW __wur; extern int __REDIRECT_NTH (ftruncate, (int __fd, __off64_t __length), 			  ftruncate64) __wur; extern int ftruncate64 (int __fd, __off64_t __length) __THROW __wur; /* Set the end of accessible data space (aka "the break") to ADDR. Returns zero on success and -1 for errors (with errno set). */ extern int brk (void *__addr) __THROW __wur; /* Increase or decrease the end of accessible data space by DELTA bytes. If successful, returns the address the previous end of data space (i.e. the beginning of the new space, if DELTA > 0); returns (void *) -1 for errors (with errno set). */ extern void *sbrk (intptr_t __delta) __THROW; /* 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 long int syscall (long int __sysno, ...) __THROW; /* NOTE: These declarations also appear in ; 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. This function is a cancellation point and therefore not marked with __THROW. */ extern int lockf (int __fd, int __cmd, __off_t __len) __wur; extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len), 		      lockf64) __wur; extern int lockf64 (int __fd, int __cmd, __off64_t __len) __wur; /* Evaluate EXPRESSION, and repeat as long as it returns -1 with `errno' set to EINTR. */  (__extension__							      \     ({ long int __result;						      \ do __result = (long int) (expression);				     \ while (__result == -1L && errno == EINTR);			     \ __result; })) /* Synchronize at least the data part of a file with the underlying media. */ extern int fdatasync (int __fildes); /* XPG4.2 specifies that prototypes for the encryption functions must be defined here. */ /* Encrypt at most 8 characters from KEY using salt to perturb DES. */ extern char *crypt (__const char *__key, __const char *__salt) __THROW __nonnull ((1, 2)); /* Encrypt data in BLOCK in place if EDFLAG is zero; otherwise decrypt block in place. */ extern void encrypt (char *__block, int __edflag) __THROW __nonnull ((1)); /* Swab pairs bytes in the first N bytes of the area pointed to by   FROM and copy the result to TO. The value of TO must not be in the range [FROM - N + 1, FROM - 1]. If N is odd the first byte in FROM is without partner. */ extern void swab (__const void *__restrict __from, void *__restrict __to, 		 ssize_t __n) __THROW __nonnull ((1, 2)); /* The Single Unix specification demands this prototype to be here. It is also found in . */ /* Return the name of the controlling terminal. */ extern char *ctermid (char *__s) __THROW; /* Define some macros helping to catch buffer overflows. */ __END_DECLS
 * 1) ifndef	_UNISTD_H
 * 2) define	_UNISTD_H	1
 * 1) include 
 * 1) define	_POSIX_VERSION	200112L
 * 1) define _POSIX2_VERSION	200112L
 * 1) define	_POSIX2_C_BIND	200112L
 * 1) define	_POSIX2_C_DEV	200112L
 * 1) define	_POSIX2_SW_DEV	200112L
 * 1) define _POSIX2_LOCALEDEF      200112L
 * 1) ifdef __USE_XOPEN2K
 * 2) define _XOPEN_VERSION	600
 * 3) elif defined __USE_UNIX98
 * 4) define _XOPEN_VERSION	500
 * 5) else
 * 6) define _XOPEN_VERSION	4
 * 7) endif
 * 1) define _XOPEN_XCU_VERSION	4
 * 1) define _XOPEN_XPG2	1
 * 2) define _XOPEN_XPG3	1
 * 3) define _XOPEN_XPG4	1
 * 1) define _XOPEN_UNIX	1
 * 1) define	_XOPEN_CRYPT	1
 * 1) define	_XOPEN_ENH_I18N	1
 * 1) define _XOPEN_LEGACY	1
 * 1) include 
 * 1) ifdef __USE_UNIX98
 * 2) include 
 * 3) endif
 * 1) define	STDIN_FILENO	0	/* Standard input. */
 * 2) define	STDOUT_FILENO	1	/* Standard output. */
 * 3) define	STDERR_FILENO	2	/* Standard error output. */
 * 1) include 
 * 1) ifndef	__ssize_t_defined
 * 1) define __ssize_t_defined
 * 2) endif
 * 1) define	__need_size_t
 * 2) define __need_NULL
 * 3) include 
 * 1) if defined __USE_XOPEN || defined __USE_XOPEN2K
 * 1) ifndef __gid_t_defined
 * 1)  define __gid_t_defined
 * 2) endif
 * 1) ifndef __uid_t_defined
 * 1)  define __uid_t_defined
 * 2) endif
 * 1) ifndef __off_t_defined
 * 2)  ifndef __USE_FILE_OFFSET64
 * 1)  else
 * 1)  endif
 * 2)  define __off_t_defined
 * 3) endif
 * 4) if defined __USE_LARGEFILE64 && !defined __off64_t_defined
 * 1)  define __off64_t_defined
 * 2) endif
 * 1) ifndef __useconds_t_defined
 * 1)  define __useconds_t_defined
 * 2) endif
 * 1) ifndef __pid_t_defined
 * 1)  define __pid_t_defined
 * 2) endif
 * 3) endif	/* X/Open */
 * 1) if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 * 2) ifndef __intptr_t_defined
 * 1)  define __intptr_t_defined
 * 2) endif
 * 3) endif
 * 1) if defined __USE_BSD || defined __USE_XOPEN
 * 2) ifndef __socklen_t_defined
 * 1)  define __socklen_t_defined
 * 2) endif
 * 3) endif
 * 1) define	R_OK	4		/* Test for read permission. */
 * 2) define	W_OK	2		/* Test for write permission. */
 * 3) define	X_OK	1		/* Test for execute permission. */
 * 4) define	F_OK	0		/* Test for existence. */
 * 1) ifdef __USE_GNU
 * 1) endif
 * 1) ifdef __USE_ATFILE
 * 1) endif /* Use GNU. */
 * 1) ifndef	_STDIO_H		/*  has the same definitions. */
 * 2) define SEEK_SET	0	/* Seek from beginning of file.  */
 * 3) define SEEK_CUR	1	/* Seek from current position.  */
 * 4) define SEEK_END	2	/* Seek from end of file.  */
 * 5) endif
 * 1) if defined __USE_BSD && !defined L_SET
 * 1) define L_SET		SEEK_SET
 * 2) define L_INCR		SEEK_CUR
 * 3) define L_XTND		SEEK_END
 * 4) endif
 * 1) ifndef __USE_FILE_OFFSET64
 * 1) else
 * 2) ifdef __REDIRECT_NTH
 * 1) else
 * 2)  define lseek lseek64
 * 3) endif
 * 4) endif
 * 5) ifdef __USE_LARGEFILE64
 * 1) endif
 * 1) ifdef __USE_UNIX98
 * 2) ifndef __USE_FILE_OFFSET64
 * 1) else
 * 2)  ifdef __REDIRECT
 * 1)  else
 * 2)   define pread pread64
 * 3)   define pwrite pwrite64
 * 4)  endif
 * 5) endif
 * 1) ifdef __USE_LARGEFILE64
 * 1) endif
 * 2) endif
 * 1) if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 * 1) endif
 * 1) if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 * 1) endif /* Use BSD || X/Open Unix. */
 * 1) ifdef __USE_ATFILE
 * 1) endif /* Use GNU. */
 * 1) if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 * 1) endif
 * 1) ifdef	__USE_GNU
 * 1) endif
 * 1) if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 * 1) endif
 * 1) ifdef __USE_GNU
 * 1) endif
 * 1) ifdef __USE_GNU
 * 1) endif
 * 1) if defined __USE_MISC || defined __USE_XOPEN
 * 1) endif
 * 1) include 
 * 1) ifdef	__USE_POSIX2
 * 1) endif
 * 1) ifndef __FAVOR_BSD
 * 1) else
 * 2) ifdef __REDIRECT_NTH
 * 1) else
 * 2)  define getpgrp __getpgid
 * 3) endif
 * 4) endif
 * 1) ifdef __USE_XOPEN_EXTENDED
 * 1) endif
 * 1) if defined __USE_SVID || defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 * 1) ifndef __FAVOR_BSD
 * 1) else
 * 1)  ifdef __REDIRECT_NTH
 * 1)  else
 * 2)   define setpgrp setpgid
 * 3)  endif
 * 1) endif	/* Favor BSD.  */
 * 2) endif	/* Use SVID or BSD. */
 * 1) ifdef __USE_XOPEN_EXTENDED
 * 1) endif
 * 1) ifdef	__USE_GNU
 * 1) endif
 * 1) if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 * 1) endif
 * 1) if defined __USE_BSD || defined __USE_XOPEN2K
 * 1) endif /* Use BSD. */
 * 1) if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 * 1) endif
 * 1) if defined __USE_BSD || defined __USE_XOPEN2K
 * 1) endif /* Use BSD. */
 * 1) ifdef __USE_GNU
 * 1) endif
 * 1) if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 * 1) endif /* Use BSD. */
 * 1) if defined __USE_BSD \
 * 1) endif
 * 1) ifdef __USE_ATFILE
 * 1) endif
 * 1) if defined __USE_BSD || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
 * 1) endif /* Use BSD. */
 * 1) ifdef __USE_ATFILE
 * 1) endif
 * 1) ifdef __USE_ATFILE
 * 1) endif
 * 1) if defined __USE_REENTRANT || defined __USE_POSIX199506
 * 1) endif
 * 1) ifdef	__USE_BSD
 * 1) endif
 * 1) ifdef	__USE_POSIX2
 * 1) define __need_getopt
 * 2) include 
 * 3) endif
 * 1) if defined __USE_BSD || defined __USE_UNIX98
 * 1) endif
 * 1) if defined __USE_BSD || (defined __USE_XOPEN && !defined __USE_UNIX98)
 * 1) endif /* Use BSD || X/Open. */
 * 1) if defined __USE_BSD || (defined __USE_XOPEN && !defined __USE_XOPEN2K)
 * 1) endif /* Use BSD || X/Open. */
 * 1) if defined __USE_BSD || defined __USE_XOPEN
 * 1) endif /* Use BSD || X/Open. */
 * 1) if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 * 1) ifndef __USE_FILE_OFFSET64
 * 1) else
 * 2)  ifdef __REDIRECT_NTH
 * 1)  else
 * 2)   define truncate truncate64
 * 3)  endif
 * 4) endif
 * 5) ifdef __USE_LARGEFILE64
 * 1) endif
 * 1) endif /* Use BSD || X/Open Unix. */
 * 1) if defined __USE_BSD || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
 * 1) ifndef __USE_FILE_OFFSET64
 * 1) else
 * 2)  ifdef __REDIRECT_NTH
 * 1)  else
 * 2)   define ftruncate ftruncate64
 * 3)  endif
 * 4) endif
 * 5) ifdef __USE_LARGEFILE64
 * 1) endif
 * 1) endif /* Use BSD || X/Open Unix || POSIX 2003. */
 * 1) if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 * 1) endif
 * 1) ifdef __USE_MISC
 * 1) endif	/* Use misc. */
 * 1) if (defined __USE_MISC || defined __USE_XOPEN_EXTENDED) && !defined F_LOCK
 * 1) define F_ULOCK 0	/* Unlock a previously locked region.  */
 * 2) define F_LOCK  1	/* Lock a region for exclusive use.  */
 * 3) define F_TLOCK 2	/* Test and lock a region for exclusive use.  */
 * 4) define F_TEST  3	/* Test a region for other processes locks.  */
 * 1) ifndef __USE_FILE_OFFSET64
 * 1) else
 * 2)  ifdef __REDIRECT
 * 1)  else
 * 2)   define lockf lockf64
 * 3)  endif
 * 4) endif
 * 5) ifdef __USE_LARGEFILE64
 * 1) endif
 * 2) endif /* Use misc and F_LOCK not already defined. */
 * 1) ifdef __USE_GNU
 * 1) define TEMP_FAILURE_RETRY(expression) \
 * 1) endif
 * 1) if defined __USE_POSIX199309 || defined __USE_UNIX98
 * 1) endif /* Use POSIX199309 */
 * 1) ifdef	__USE_XOPEN
 * 1) endif
 * 1) ifdef __USE_XOPEN
 * 1) endif
 * 1) if __USE_FORTIFY_LEVEL > 0 && !defined __cplusplus
 * 2) include 
 * 3) endif
 * 1) endif /* unistd.h */