bits/fcntl.h

   1 /* O_*, F_*, FD_* bit values. 4.4BSD/Generic version.
   2    Copyright (C) 1991-2023 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _FCNTL_H
  20 #error "Never use <bits/fcntl.h> directly; include <fcntl.h> instead."
  21 #endif
  22
  23
  24 /* File access modes for `open' and `fcntl'.  */
  25 #define O_RDONLY        0       /* Open read-only.  */
  26 #define O_WRONLY        1       /* Open write-only.  */
  27 #define O_RDWR          2       /* Open read/write.  */
  28
  29
  30 /* Bits OR'd into the second argument to open.  */
  31 #define O_CREAT         0x0200  /* Create file if it doesn't exist.  */
  32 #define O_EXCL          0x0800  /* Fail if file already exists.  */
  33 #define O_TRUNC         0x0400  /* Truncate file to zero length.  */
  34 #define O_NOCTTY        0x8000  /* Don't assign a controlling terminal.  */
  35 #define O_ASYNC         0x0040  /* Send SIGIO to owner when data is ready.  */
  36 #define O_FSYNC         0x0080  /* Synchronous writes.  */
  37 #define O_SYNC          O_FSYNC
  38 #ifdef  __USE_MISC
  39 #define O_SHLOCK        0x0010  /* Open with shared file lock.  */
  40 #define O_EXLOCK        0x0020  /* Open with shared exclusive lock.  */
  41 #endif
  42 #ifdef __USE_XOPEN2K8
  43 # define O_DIRECTORY    0x00200000      /* Must be a directory.  */
  44 # define O_NOFOLLOW     0x00000100      /* Do not follow links.  */
  45 # define O_CLOEXEC      0x00400000      /* Set close_on_exec.  */
  46 #endif
  47 #if defined __USE_POSIX199309 || defined __USE_UNIX98
  48 # define O_DSYNC        0x00010000      /* Synchronize data.  */
  49 # define O_RSYNC        0x00020000      /* Synchronize read operations.  */
  50 #endif
  51
  52 /* All opens support large file sizes, so there is no flag bit for this.  */
  53 #ifdef __USE_LARGEFILE64
  54 # define O_LARGEFILE    0
  55 #endif
  56
  57 /* File status flags for `open' and `fcntl'.  */
  58 #define O_APPEND        0x0008  /* Writes append to the file.  */
  59 #define O_NONBLOCK      0x0004  /* Non-blocking I/O.  */
  60
  61 #ifdef __USE_MISC
  62 # define O_NDELAY       O_NONBLOCK
  63 #endif
  64
  65 #ifdef __USE_MISC
  66 /* Flags for TIOCFLUSH.  */
  67 # define FREAD          1
  68 # define FWRITE         2
  69
  70 /* Traditional BSD names the O_* bits.  */
  71 # define FASYNC         O_ASYNC
  72 # define FFSYNC         O_FSYNC
  73 # define FSYNC          O_SYNC
  74 # define FAPPEND        O_APPEND
  75 # define FNDELAY        O_NDELAY
  76 #endif
  77
  78 /* Mask for file access modes.  This is system-dependent in case
  79    some system ever wants to define some other flavor of access.  */
  80 #define O_ACCMODE       (O_RDONLY|O_WRONLY|O_RDWR)
  81
  82 /* Values for the second argument to `fcntl'.  */
  83 #define F_DUPFD         0       /* Duplicate file descriptor.  */
  84 #define F_GETFD         1       /* Get file descriptor flags.  */
  85 #define F_SETFD         2       /* Set file descriptor flags.  */
  86 #define F_GETFL         3       /* Get file status flags.  */
  87 #define F_SETFL         4       /* Set file status flags.  */
  88 #if defined __USE_UNIX98 || defined __USE_XOPEN2K8
  89 #define F_GETOWN        5       /* Get owner (receiver of SIGIO).  */
  90 #define F_SETOWN        6       /* Set owner (receiver of SIGIO).  */
  91 #endif
  92 #define F_GETLK         7       /* Get record locking info.  */
  93 #define F_SETLK         8       /* Set record locking info (non-blocking).  */
  94 #define F_SETLKW        9       /* Set record locking info (blocking).  */
  95 /* Not necessary, we always have 64-bit offsets.  */
  96 #define F_GETLK64       F_GETLK /* Get record locking info.  */
  97 #define F_SETLK64       F_SETLK /* Set record locking info (non-blocking).  */
  98 #define F_SETLKW64      F_SETLKW/* Set record locking info (blocking).  */
  99 #ifdef __USE_XOPEN2K8
 100 # define F_DUPFD_CLOEXEC 12     /* Duplicate file descriptor with
 101                                    close-on-exit set.  */
 102 #endif
 103
 104 /* File descriptor flags used with F_GETFD and F_SETFD.  */
 105 #define FD_CLOEXEC      1       /* Close on exec.  */
 106
 107
 108 #include <bits/types.h>
 109
 110 /* The structure describing an advisory lock.  This is the type of the third
 111    argument to `fcntl' for the F_GETLK, F_SETLK, and F_SETLKW requests.  */
 112 struct flock
 113   {
 114     __off_t l_start;    /* Offset where the lock begins.  */
 115     __off_t l_len;      /* Size of the locked area; zero means until EOF.  */
 116     __pid_t l_pid;      /* Process holding the lock.  */
 117     short int l_type;   /* Type of lock: F_RDLCK, F_WRLCK, or F_UNLCK.  */
 118     short int l_whence; /* Where `l_start' is relative to (like `lseek').  */
 119   };
 120
 121 #ifdef __USE_LARGEFILE64
 122 /* Note this matches struct flock exactly.  */
 123 struct flock64
 124   {
 125     __off_t l_start;    /* Offset where the lock begins.  */
 126     __off_t l_len;      /* Size of the locked area; zero means until EOF.  */
 127     __pid_t l_pid;      /* Process holding the lock.  */
 128     short int l_type;   /* Type of lock: F_RDLCK, F_WRLCK, or F_UNLCK.  */
 129     short int l_whence; /* Where `l_start' is relative to (like `lseek').  */
 130   };
 131 #endif
 132
 133 /* Values for the `l_type' field of a `struct flock'.  */
 134 #define F_RDLCK 1       /* Read lock.  */
 135 #define F_WRLCK 2       /* Write lock.  */
 136 #define F_UNLCK 3       /* Remove lock.  */
 137
 138 /* Advise to `posix_fadvise'.  */
 139 #ifdef __USE_XOPEN2K
 140 # define POSIX_FADV_NORMAL      0 /* No further special treatment.  */
 141 # define POSIX_FADV_RANDOM      1 /* Expect random page references.  */
 142 # define POSIX_FADV_SEQUENTIAL  2 /* Expect sequential page references.  */
 143 # define POSIX_FADV_WILLNEED    3 /* Will need these pages.  */
 144 # define POSIX_FADV_DONTNEED    4 /* Don't need these pages.  */
 145 # define POSIX_FADV_NOREUSE     5 /* Data will be accessed once.  */
 146 #endif