sysdeps/unix/sysv/bits/fcntl.h

   1 /* O_*, F_*, FD_* bit values for System V.
   2    Copyright (C) 1991, 1992, 1997 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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #ifndef _FCNTL_H
  21 #error "Never use <bits/fcntl.h> directly; include <fcntl.h> instead."
  22 #endif
  23
  24
  25 /* File access modes for `open' and `fcntl'.  */
  26 #define O_RDONLY        0       /* Open read-only.  */
  27 #define O_WRONLY        1       /* Open write-only.  */
  28 #define O_RDWR          2       /* Open read/write.  */
  29
  30
  31 /* Bits OR'd into the second argument to open.  */
  32 #define O_CREAT         00400   /* Create file if it doesn't exist.  */
  33 #define O_EXCL          02000   /* Fail if file already exists.  */
  34 #define O_TRUNC         01000   /* Truncate file to zero length.  */
  35 #if defined __USE_BSD || defined __USE_SVID
  36 #define O_SYNC          00020   /* Synchronous writes.  */
  37 #define O_FSYNC         O_SYNC
  38 #endif
  39
  40 /* File status flags for `open' and `fcntl'.  */
  41 #define O_APPEND        000010  /* Writes append to the file.  */
  42 #define O_NONBLOCK      000004  /* Non-blocking I/O.  */
  43
  44 #ifdef __USE_BSD
  45 /* System V doesn't support POSIX.1 O_NONBLOCK, but O_NDELAY is close.  */
  46 #define O_NDELAY        O_NONBLOCK
  47 #endif
  48
  49 /* Mask for file access modes.  This is system-dependent in case
  50    some system ever wants to define some other flavor of access.  */
  51 #define O_ACCMODE       (O_RDONLY|O_WRONLY|O_RDWR)
  52
  53 /* Values for the second argument to `fcntl'.  */
  54 #define F_DUPFD         0       /* Duplicate file descriptor.  */
  55 #define F_GETFD         1       /* Get file descriptor flags.  */
  56 #define F_SETFD         2       /* Set file descriptor flags.  */
  57 #define F_GETFL         3       /* Get file status flags.  */
  58 #define F_SETFL         4       /* Set file status flags.  */
  59 #define F_GETLK         5       /* Get record locking info.  */
  60 #define F_SETLK         6       /* Set record locking info.  */
  61 #define F_SETLKW        7       /* Set record locking info, wait.  */
  62
  63 /* File descriptor flags used with F_GETFD and F_SETFD.  */
  64 #define FD_CLOEXEC      1       /* Close on exec.  */
  65
  66
  67 #include <bits/types.h>
  68
  69 /* The structure describing an advisory lock.  This is the type of the third
  70    argument to `fcntl' for the F_GETLK, F_SETLK, and F_SETLKW requests.  */
  71 struct flock
  72   {
  73     short int l_type;   /* Type of lock: F_RDLCK, F_WRLCK, or F_UNLCK.  */
  74     short int l_whence; /* Where `l_start' is relative to (like `lseek').  */
  75     __off_t l_start;    /* Offset where the lock begins.  */
  76     __off_t l_len;      /* Size of the locked area; zero means until EOF.  */
  77     short int l_sysid;  /* System ID where locking process resides. */
  78     short int l_pid;    /* Process holding the lock.  */
  79   };
  80
  81 /* Values for the `l_type' field of a `struct flock'.  */
  82 #define F_RDLCK 1       /* Read lock.  */
  83 #define F_WRLCK 2       /* Write lock.  */
  84 #define F_UNLCK 3       /* Remove lock.  */
  85
  86
  87 /* Define some more compatibility macros to be backward compatible with
  88    BSD systems which did not managed to hide these kernel macros.  */
  89 #ifdef  __USE_BSD
  90 #define FAPPEND         O_APPEND
  91 #define FFSYNC          O_FSYNC
  92 #define FNONBLOCK       O_NONBLOCK
  93 #define FNDELAY         O_NDELAY
  94 #endif /* Use BSD.  */