mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-26 23:10:06 +00:00
39120df9b9
Add comments to fcntl.h explaining why AT_REMOVEDIR and AT_EACCESS can have the same value.
308 lines
10 KiB
C
308 lines
10 KiB
C
/* Copyright (C) 1991-2013 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
|
|
<http://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>
|
|
|
|
/* 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. */
|
|
#if defined __USE_XOPEN || defined __USE_XOPEN2K8
|
|
# define __need_timespec
|
|
# include <time.h>
|
|
# 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_BSD || 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_EASSESS
|
|
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. */
|
|
# 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. */
|
|
extern int fcntl (int __fd, int __cmd, ...);
|
|
|
|
/* Open FILE and return a new file descriptor for it, or -1 on error.
|
|
OFLAG determines the type of access used. If O_CREAT is on 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 */
|