gl/unistd_.h

   1 /* Substitute for and wrapper around <unistd.h>.
   2    Copyright (C) 2004-2007 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 2, or (at your option)
   7    any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software Foundation,
  16    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  17
  18 #ifndef _GL_UNISTD_H
  19 #define _GL_UNISTD_H
  20
  21 #if @HAVE_UNISTD_H@
  22 # if @HAVE_INCLUDE_NEXT@
  23 #  include_next <unistd.h>
  24 # else
  25 #  include @ABSOLUTE_UNISTD_H@
  26 # endif
  27 #endif
  28
  29 /* mingw doesn't define the SEEK_* macros in <unistd.h>.  */
  30 #if !(defined SEEK_CUR && defined SEEK_END && defined SEEK_SET)
  31 # include <stdio.h>
  32 #endif
  33
  34 /* mingw fails to declare _exit in <unistd.h>.  */
  35 #include <stdlib.h>
  36
  37 /* The definition of GL_LINK_WARNING is copied here.  */
  38
  39
  40 /* Declare overridden functions.  */
  41
  42 #ifdef __cplusplus
  43 extern "C" {
  44 #endif
  45
  46
  47 #if @GNULIB_CHOWN@
  48 # if @REPLACE_CHOWN@
  49 /* Change the owner of FILE to UID (if UID is not -1) and the group of FILE
  50    to GID (if GID is not -1).
  51    Return 0 if successful, otherwise -1 and errno set.
  52    See the POSIX:2001 specification
  53    <http://www.opengroup.org/susv3xsh/chown.html>.  */
  54 #  define chown rpl_chown
  55 extern int chown (const char *file, uid_t uid, gid_t gid);
  56 # endif
  57 #elif defined GNULIB_POSIXCHECK
  58 # undef chown
  59 # define chown(f,u,g) \
  60     (GL_LINK_WARNING ("chown fails to follow symlinks on some systems and " \
  61                       "doesn't treat a uid or gid of -1 on some systems - " \
  62                       "use gnulib module chown for portability"), \
  63      chown (f, u, g))
  64 #endif
  65
  66
  67 #if @GNULIB_DUP2@
  68 # if !@HAVE_DUP2@
  69 /* Copy the file descriptor OLDFD into file descriptor NEWFD.  Do nothing if
  70    NEWFD = OLDFD, otherwise close NEWFD first if it is open.
  71    Return 0 if successful, otherwise -1 and errno set.
  72    See the POSIX:2001 specification
  73    <http://www.opengroup.org/susv3xsh/dup2.html>.  */
  74 extern int dup2 (int oldfd, int newfd);
  75 # endif
  76 #elif defined GNULIB_POSIXCHECK
  77 # undef dup2
  78 # define dup2(o,n) \
  79     (GL_LINK_WARNING ("dup2 is unportable - " \
  80                       "use gnulib module dup2 for portability"), \
  81      dup2 (o, n))
  82 #endif
  83
  84
  85 #if @GNULIB_FCHDIR@
  86 # if @REPLACE_FCHDIR@
  87
  88 /* Change the process' current working directory to the directory on which
  89    the given file descriptor is open.
  90    Return 0 if successful, otherwise -1 and errno set.
  91    See the POSIX:2001 specification
  92    <http://www.opengroup.org/susv3xsh/fchdir.html>.  */
  93 extern int fchdir (int /*fd*/);
  94
  95 #  define close rpl_close
  96 extern int close (int);
  97 #  define dup rpl_dup
  98 extern int dup (int);
  99 #  define dup2 rpl_dup2
 100 extern int dup2 (int, int);
 101
 102 # endif
 103 #elif defined GNULIB_POSIXCHECK
 104 # undef fchdir
 105 # define fchdir(f) \
 106     (GL_LINK_WARNING ("fchdir is unportable - " \
 107                       "use gnulib module fchdir for portability"), \
 108      fchdir (f))
 109 #endif
 110
 111
 112 #if @GNULIB_FTRUNCATE@
 113 # if !@HAVE_FTRUNCATE@
 114 /* Change the size of the file to which FD is opened to become equal to LENGTH.
 115    Return 0 if successful, otherwise -1 and errno set.
 116    See the POSIX:2001 specification
 117    <http://www.opengroup.org/susv3xsh/ftruncate.html>.  */
 118 extern int ftruncate (int fd, off_t length);
 119 # endif
 120 #elif defined GNULIB_POSIXCHECK
 121 # undef ftruncate
 122 # define ftruncate(f,l) \
 123     (GL_LINK_WARNING ("ftruncate is unportable - " \
 124                       "use gnulib module ftruncate for portability"), \
 125      ftruncate (f, l))
 126 #endif
 127
 128
 129 #if @GNULIB_GETCWD@
 130 /* Include the headers that might declare getcwd so that they will not
 131    cause confusion if included after this file.  */
 132 # include <stdlib.h>
 133 # if @REPLACE_GETCWD@
 134 /* Get the name of the current working directory, and put it in SIZE bytes
 135    of BUF.
 136    Return BUF if successful, or NULL if the directory couldn't be determined
 137    or SIZE was too small.
 138    See the POSIX:2001 specification
 139    <http://www.opengroup.org/susv3xsh/getcwd.html>.
 140    Additionally, the gnulib module 'getcwd' guarantees the following GNU
 141    extension: If BUF is NULL, an array is allocated with 'malloc'; the array
 142    is SIZE bytes long, unless SIZE == 0, in which case it is as big as
 143    necessary.  */
 144 #  define getcwd rpl_getcwd
 145 extern char * getcwd (char *buf, size_t size);
 146 # endif
 147 #elif defined GNULIB_POSIXCHECK
 148 # undef getcwd
 149 # define getcwd(b,s) \
 150     (GL_LINK_WARNING ("getcwd is unportable - " \
 151                       "use gnulib module getcwd for portability"), \
 152      getcwd (b, s))
 153 #endif
 154
 155
 156 #if @GNULIB_GETLOGIN_R@
 157 /* Copies the user's login name to NAME.
 158    The array pointed to by NAME has room for SIZE bytes.
 159
 160    Returns 0 if successful.  Upon error, an error number is returned, or -1 in
 161    the case that the login name cannot be found but no specific error is
 162    provided (this case is hopefully rare but is left open by the POSIX spec).
 163
 164    See <http://www.opengroup.org/susv3xsh/getlogin.html>.
 165  */
 166 # if !@HAVE_DECL_GETLOGIN_R@
 167 #  include <stddef.h>
 168 extern int getlogin_r (char *name, size_t size);
 169 # endif
 170 #elif defined GNULIB_POSIXCHECK
 171 # undef getlogin_r
 172 # define getlogin_r(n,s) \
 173     (GL_LINK_WARNING ("getlogin_r is unportable - " \
 174                       "use gnulib module getlogin_r for portability"), \
 175      getlogin_r (n, s))
 176 #endif
 177
 178
 179 #if @GNULIB_READLINK@
 180 /* Read the contents of the symbolic link FILE and place the first BUFSIZE
 181    bytes of it into BUF.  Return the number of bytes placed into BUF if
 182    successful, otherwise -1 and errno set.
 183    See the POSIX:2001 specification
 184    <http://www.opengroup.org/susv3xsh/readlink.html>.  */
 185 # if !@HAVE_READLINK@
 186 #  include <stddef.h>
 187 extern int readlink (const char *file, char *buf, size_t bufsize);
 188 # endif
 189 #elif defined GNULIB_POSIXCHECK
 190 # undef readlink
 191 # define readlink(f,b,s) \
 192     (GL_LINK_WARNING ("readlink is unportable - " \
 193                       "use gnulib module readlink for portability"), \
 194      readlink (f, b, s))
 195 #endif
 196
 197
 198 #if @GNULIB_SLEEP@
 199 /* Pause the execution of the current thread for N seconds.
 200    Returns the number of seconds left to sleep.
 201    See the POSIX:2001 specification
 202    <http://www.opengroup.org/susv3xsh/sleep.html>.  */
 203 # if !@HAVE_SLEEP@
 204 extern unsigned int sleep (unsigned int n);
 205 # endif
 206 #elif defined GNULIB_POSIXCHECK
 207 # undef sleep
 208 # define sleep(n) \
 209     (GL_LINK_WARNING ("sleep is unportable - " \
 210                       "use gnulib module sleep for portability"), \
 211      sleep (n))
 212 #endif
 213
 214
 215 #ifdef __cplusplus
 216 }
 217 #endif
 218
 219
 220 #endif /* _GL_UNISTD_H */