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Edit File: fcntl.h
/* Copyright (C) 1991-2021 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, see <https://www.gnu.org/licenses/>. */ /* * POSIX Standard: 6.5 File Control Operations <fcntl.h> */ #ifndef _FCNTL_H #define _FCNTL_H 1 #include <features.h> /* This must be early so <bits/fcntl.h> can define types winningly. */ __BEGIN_DECLS /* Get __mode_t, __dev_t and __off_t .*/ #include <bits/types.h> /* Get the definitions of O_*, F_*, FD_*: all the numbers and flag bits for `open', `fcntl', et al. */ #include <bits/fcntl.h> /* Detect if open needs mode as a third argument (or for openat as a fourth argument). */ #ifdef __O_TMPFILE # define __OPEN_NEEDS_MODE(oflag) \ (((oflag) & O_CREAT) != 0 || ((oflag) & __O_TMPFILE) == __O_TMPFILE) #else # define __OPEN_NEEDS_MODE(oflag) (((oflag) & O_CREAT) != 0) #endif /* POSIX.1-2001 specifies that these types are defined by <fcntl.h>. Earlier POSIX standards permitted any type ending in `_t' to be defined by any POSIX header, so we don't conditionalize the definitions here. */ #ifndef __mode_t_defined typedef __mode_t mode_t; # define __mode_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 __pid_t_defined typedef __pid_t pid_t; # define __pid_t_defined #endif /* For XPG all symbols from <sys/stat.h> should also be available. */ #ifdef __USE_XOPEN2K8 # include <bits/types/struct_timespec.h> #endif #if defined __USE_XOPEN || defined __USE_XOPEN2K8 # include <bits/stat.h> # define S_IFMT __S_IFMT # define S_IFDIR __S_IFDIR # define S_IFCHR __S_IFCHR # define S_IFBLK __S_IFBLK # define S_IFREG __S_IFREG # ifdef __S_IFIFO # define S_IFIFO __S_IFIFO # endif # ifdef __S_IFLNK # define S_IFLNK __S_IFLNK # endif # if (defined __USE_UNIX98 || defined __USE_XOPEN2K8) && defined __S_IFSOCK # define S_IFSOCK __S_IFSOCK # endif /* Protection bits. */ # define S_ISUID __S_ISUID /* Set user ID on execution. */ # define S_ISGID __S_ISGID /* Set group ID on execution. */ # if defined __USE_MISC || defined __USE_XOPEN /* Save swapped text after use (sticky bit). This is pretty well obsolete. */ # define S_ISVTX __S_ISVTX # endif # define S_IRUSR __S_IREAD /* Read by owner. */ # define S_IWUSR __S_IWRITE /* Write by owner. */ # define S_IXUSR __S_IEXEC /* Execute by owner. */ /* Read, write, and execute by owner. */ # define S_IRWXU (__S_IREAD|__S_IWRITE|__S_IEXEC) # define S_IRGRP (S_IRUSR >> 3) /* Read by group. */ # define S_IWGRP (S_IWUSR >> 3) /* Write by group. */ # define S_IXGRP (S_IXUSR >> 3) /* Execute by group. */ /* Read, write, and execute by group. */ # define S_IRWXG (S_IRWXU >> 3) # define S_IROTH (S_IRGRP >> 3) /* Read by others. */ # define S_IWOTH (S_IWGRP >> 3) /* Write by others. */ # define S_IXOTH (S_IXGRP >> 3) /* Execute by others. */ /* Read, write, and execute by others. */ # define S_IRWXO (S_IRWXG >> 3) #endif #ifdef __USE_MISC # ifndef R_OK /* Verbatim from <unistd.h>. Ugh. */ /* 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. */ # endif #endif /* Use misc. */ /* XPG wants the following symbols. <stdio.h> has the same definitions. */ #if defined __USE_XOPEN || defined __USE_XOPEN2K8 # 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 /* XPG */ /* The constants AT_REMOVEDIR and AT_EACCESS have the same value. AT_EACCESS is meaningful only to faccessat, while AT_REMOVEDIR is meaningful only to unlinkat. The two functions do completely different things and therefore, the flags can be allowed to overlap. For example, passing AT_REMOVEDIR to faccessat would be undefined behavior and thus treating it equivalent to AT_EACCESS is valid undefined behavior. */ #ifdef __USE_ATFILE # define AT_FDCWD -100 /* Special value used to indicate the *at functions should use the current working directory. */ # define AT_SYMLINK_NOFOLLOW 0x100 /* Do not follow symbolic links. */ # define AT_REMOVEDIR 0x200 /* Remove directory instead of unlinking file. */ # define AT_SYMLINK_FOLLOW 0x400 /* Follow symbolic links. */ # ifdef __USE_GNU # define AT_NO_AUTOMOUNT 0x800 /* Suppress terminal automount traversal. */ # define AT_EMPTY_PATH 0x1000 /* Allow empty relative pathname. */ # define AT_STATX_SYNC_TYPE 0x6000 # define AT_STATX_SYNC_AS_STAT 0x0000 # define AT_STATX_FORCE_SYNC 0x2000 # define AT_STATX_DONT_SYNC 0x4000 # define AT_RECURSIVE 0x8000 /* Apply to the entire subtree. */ # endif # define AT_EACCESS 0x200 /* Test access permitted for effective IDs, not real IDs. */ #endif /* Do the file control operation described by CMD on FD. The remaining arguments are interpreted depending on CMD. This function is a cancellation point and therefore not marked with __THROW. */ #ifndef __USE_TIME_BITS64 # ifndef __USE_FILE_OFFSET64 extern int fcntl (int __fd, int __cmd, ...); # else # ifdef __REDIRECT extern int __REDIRECT (fcntl, (int __fd, int __cmd, ...), fcntl64); # else # define fcntl fcntl64 # endif # endif # ifdef __USE_LARGEFILE64 extern int fcntl64 (int __fd, int __cmd, ...); # endif #else /* __USE_TIME_BITS64 */ # ifdef __REDIRECT extern int __REDIRECT_NTH (fcntl, (int __fd, int __request, ...), __fcntl_time64); extern int __REDIRECT_NTH (fcntl64, (int __fd, int __request, ...), __fcntl_time64); # else extern int __fcntl_time64 (int __fd, int __request, ...) __THROW; # define fcntl64 __fcntl_time64 # define fcntl __fcntl_time64 # endif #endif /* Open FILE and return a new file descriptor for it, or -1 on error. OFLAG determines the type of access used. If O_CREAT or O_TMPFILE is set in OFLAG, the third argument is taken as a `mode_t', the mode of the created file. This function is a cancellation point and therefore not marked with __THROW. */ #ifndef __USE_FILE_OFFSET64 extern int open (const char *__file, int __oflag, ...) __nonnull ((1)); #else # ifdef __REDIRECT extern int __REDIRECT (open, (const char *__file, int __oflag, ...), open64) __nonnull ((1)); # else # define open open64 # endif #endif #ifdef __USE_LARGEFILE64 extern int open64 (const char *__file, int __oflag, ...) __nonnull ((1)); #endif #ifdef __USE_ATFILE /* Similar to `open' but a relative path name is interpreted relative to the directory for which FD is a descriptor. NOTE: some other `openat' implementation support additional functionality through this interface, especially using the O_XATTR flag. This is not yet supported here. This function is a cancellation point and therefore not marked with __THROW. */ # ifndef __USE_FILE_OFFSET64 extern int openat (int __fd, const char *__file, int __oflag, ...) __nonnull ((2)); # else # ifdef __REDIRECT extern int __REDIRECT (openat, (int __fd, const char *__file, int __oflag, ...), openat64) __nonnull ((2)); # else # define openat openat64 # endif # endif # ifdef __USE_LARGEFILE64 extern int openat64 (int __fd, const char *__file, int __oflag, ...) __nonnull ((2)); # endif #endif /* Create and open FILE, with mode MODE. This takes an `int' MODE argument because that is what `mode_t' will be widened to. This function is a cancellation point and therefore not marked with __THROW. */ #ifndef __USE_FILE_OFFSET64 extern int creat (const char *__file, mode_t __mode) __nonnull ((1)); #else # ifdef __REDIRECT extern int __REDIRECT (creat, (const char *__file, mode_t __mode), creat64) __nonnull ((1)); # else # define creat creat64 # endif #endif #ifdef __USE_LARGEFILE64 extern int creat64 (const char *__file, mode_t __mode) __nonnull ((1)); #endif #if !defined F_LOCK && (defined __USE_MISC || (defined __USE_XOPEN_EXTENDED \ && !defined __USE_POSIX)) /* NOTE: These declarations also appear in <unistd.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. */ # ifndef __USE_FILE_OFFSET64 extern int lockf (int __fd, int __cmd, off_t __len); # else # ifdef __REDIRECT extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len), lockf64); # else # define lockf lockf64 # endif # endif # ifdef __USE_LARGEFILE64 extern int lockf64 (int __fd, int __cmd, off64_t __len); # endif #endif #ifdef __USE_XOPEN2K /* Advice the system about the expected behaviour of the application with respect to the file associated with FD. */ # ifndef __USE_FILE_OFFSET64 extern int posix_fadvise (int __fd, off_t __offset, off_t __len, int __advise) __THROW; # else # ifdef __REDIRECT_NTH extern int __REDIRECT_NTH (posix_fadvise, (int __fd, __off64_t __offset, __off64_t __len, int __advise), posix_fadvise64); # else # define posix_fadvise posix_fadvise64 # endif # endif # ifdef __USE_LARGEFILE64 extern int posix_fadvise64 (int __fd, off64_t __offset, off64_t __len, int __advise) __THROW; # endif /* Reserve storage for the data of the file associated with FD. This function is a possible cancellation point and therefore not marked with __THROW. */ # ifndef __USE_FILE_OFFSET64 extern int posix_fallocate (int __fd, off_t __offset, off_t __len); # else # ifdef __REDIRECT extern int __REDIRECT (posix_fallocate, (int __fd, __off64_t __offset, __off64_t __len), posix_fallocate64); # else # define posix_fallocate posix_fallocate64 # endif # endif # ifdef __USE_LARGEFILE64 extern int posix_fallocate64 (int __fd, off64_t __offset, off64_t __len); # endif #endif /* Define some inlines helping to catch common problems. */ #if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function \ && defined __va_arg_pack_len # include <bits/fcntl2.h> #endif __END_DECLS #endif /* fcntl.h */