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
  20 /* The include_next requires a split double-inclusion guard.  */
  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 #ifndef _GL_UNISTD_H
  30 #define _GL_UNISTD_H
  31
  32 /* mingw doesn't define the SEEK_* macros in <unistd.h>.  */
  33 #if !(defined SEEK_CUR && defined SEEK_END && defined SEEK_SET)
  34 # include <stdio.h>
  35 #endif
  36
  37 /* mingw fails to declare _exit in <unistd.h>.  */
  38 #include <stdlib.h>
  39
  40 /* The definition of GL_LINK_WARNING is copied here.  */
  41
  42
  43 /* Declare overridden functions.  */
  44
  45 #ifdef __cplusplus
  46 extern "C" {
  47 #endif
  48
  49
  50 #if @GNULIB_CHOWN@
  51 # if @REPLACE_CHOWN@
  52 /* Change the owner of FILE to UID (if UID is not -1) and the group of FILE
  53    to GID (if GID is not -1).
  54    Return 0 if successful, otherwise -1 and errno set.
  55    See the POSIX:2001 specification
  56    <http://www.opengroup.org/susv3xsh/chown.html>.  */
  57 #  define chown rpl_chown
  58 extern int chown (const char *file, uid_t uid, gid_t gid);
  59 # endif
  60 #elif defined GNULIB_POSIXCHECK
  61 # undef chown
  62 # define chown(f,u,g) \
  63     (GL_LINK_WARNING ("chown fails to follow symlinks on some systems and " \
  64                       "doesn't treat a uid or gid of -1 on some systems - " \
  65                       "use gnulib module chown for portability"), \
  66      chown (f, u, g))
  67 #endif
  68
  69
  70 #if @GNULIB_DUP2@
  71 # if !@HAVE_DUP2@
  72 /* Copy the file descriptor OLDFD into file descriptor NEWFD.  Do nothing if
  73    NEWFD = OLDFD, otherwise close NEWFD first if it is open.
  74    Return 0 if successful, otherwise -1 and errno set.
  75    See the POSIX:2001 specification
  76    <http://www.opengroup.org/susv3xsh/dup2.html>.  */
  77 extern int dup2 (int oldfd, int newfd);
  78 # endif
  79 #elif defined GNULIB_POSIXCHECK
  80 # undef dup2
  81 # define dup2(o,n) \
  82     (GL_LINK_WARNING ("dup2 is unportable - " \
  83                       "use gnulib module dup2 for portability"), \
  84      dup2 (o, n))
  85 #endif
  86
  87
  88 #if @GNULIB_FCHDIR@
  89 # if @REPLACE_FCHDIR@
  90
  91 /* Change the process' current working directory to the directory on which
  92    the given file descriptor is open.
  93    Return 0 if successful, otherwise -1 and errno set.
  94    See the POSIX:2001 specification
  95    <http://www.opengroup.org/susv3xsh/fchdir.html>.  */
  96 extern int fchdir (int /*fd*/);
  97
  98 #  define close rpl_close
  99 extern int close (int);
 100 #  define dup rpl_dup
 101 extern int dup (int);
 102 #  define dup2 rpl_dup2
 103 extern int dup2 (int, int);
 104
 105 # endif
 106 #elif defined GNULIB_POSIXCHECK
 107 # undef fchdir
 108 # define fchdir(f) \
 109     (GL_LINK_WARNING ("fchdir is unportable - " \
 110                       "use gnulib module fchdir for portability"), \
 111      fchdir (f))
 112 #endif
 113
 114
 115 #if @GNULIB_FTRUNCATE@
 116 # if !@HAVE_FTRUNCATE@
 117 /* Change the size of the file to which FD is opened to become equal to LENGTH.
 118    Return 0 if successful, otherwise -1 and errno set.
 119    See the POSIX:2001 specification
 120    <http://www.opengroup.org/susv3xsh/ftruncate.html>.  */
 121 extern int ftruncate (int fd, off_t length);
 122 # endif
 123 #elif defined GNULIB_POSIXCHECK
 124 # undef ftruncate
 125 # define ftruncate(f,l) \
 126     (GL_LINK_WARNING ("ftruncate is unportable - " \
 127                       "use gnulib module ftruncate for portability"), \
 128      ftruncate (f, l))
 129 #endif
 130
 131
 132 #if @GNULIB_GETCWD@
 133 /* Include the headers that might declare getcwd so that they will not
 134    cause confusion if included after this file.  */
 135 # include <stdlib.h>
 136 # if @REPLACE_GETCWD@
 137 /* Get the name of the current working directory, and put it in SIZE bytes
 138    of BUF.
 139    Return BUF if successful, or NULL if the directory couldn't be determined
 140    or SIZE was too small.
 141    See the POSIX:2001 specification
 142    <http://www.opengroup.org/susv3xsh/getcwd.html>.
 143    Additionally, the gnulib module 'getcwd' guarantees the following GNU
 144    extension: If BUF is NULL, an array is allocated with 'malloc'; the array
 145    is SIZE bytes long, unless SIZE == 0, in which case it is as big as
 146    necessary.  */
 147 #  define getcwd rpl_getcwd
 148 extern char * getcwd (char *buf, size_t size);
 149 # endif
 150 #elif defined GNULIB_POSIXCHECK
 151 # undef getcwd
 152 # define getcwd(b,s) \
 153     (GL_LINK_WARNING ("getcwd is unportable - " \
 154                       "use gnulib module getcwd for portability"), \
 155      getcwd (b, s))
 156 #endif
 157
 158
 159 #if @GNULIB_GETLOGIN_R@
 160 /* Copies the user's login name to NAME.
 161    The array pointed to by NAME has room for SIZE bytes.
 162
 163    Returns 0 if successful.  Upon error, an error number is returned, or -1 in
 164    the case that the login name cannot be found but no specific error is
 165    provided (this case is hopefully rare but is left open by the POSIX spec).
 166
 167    See <http://www.opengroup.org/susv3xsh/getlogin.html>.
 168  */
 169 # if !@HAVE_DECL_GETLOGIN_R@
 170 #  include <stddef.h>
 171 extern int getlogin_r (char *name, size_t size);
 172 # endif
 173 #elif defined GNULIB_POSIXCHECK
 174 # undef getlogin_r
 175 # define getlogin_r(n,s) \
 176     (GL_LINK_WARNING ("getlogin_r is unportable - " \
 177                       "use gnulib module getlogin_r for portability"), \
 178      getlogin_r (n, s))
 179 #endif
 180
 181
 182 #if @GNULIB_LSEEK@
 183 # if @REPLACE_LSEEK@
 184 /* Set the offset of FD relative to SEEK_SET, SEEK_CUR, or SEEK_END.
 185    Return the new offset if successful, otherwise -1 and errno set.
 186    See the POSIX:2001 specification
 187    <http://www.opengroup.org/susv3xsh/lseek.html>.  */
 188 #  define lseek rpl_lseek
 189    extern off_t lseek (int fd, off_t offset, int whence);
 190 # endif
 191 #elif defined GNULIB_POSIXCHECK
 192 # undef lseek
 193 # define lseek(f,o,w) \
 194     (GL_LINK_WARNING ("lseek does not fail with ESPIPE on pipes on some " \
 195                       "systems - use gnulib module lseek for portability"), \
 196      lseek (f, o, w))
 197 #endif
 198
 199
 200 #if @GNULIB_READLINK@
 201 /* Read the contents of the symbolic link FILE and place the first BUFSIZE
 202    bytes of it into BUF.  Return the number of bytes placed into BUF if
 203    successful, otherwise -1 and errno set.
 204    See the POSIX:2001 specification
 205    <http://www.opengroup.org/susv3xsh/readlink.html>.  */
 206 # if !@HAVE_READLINK@
 207 #  include <stddef.h>
 208 extern int readlink (const char *file, char *buf, size_t bufsize);
 209 # endif
 210 #elif defined GNULIB_POSIXCHECK
 211 # undef readlink
 212 # define readlink(f,b,s) \
 213     (GL_LINK_WARNING ("readlink is unportable - " \
 214                       "use gnulib module readlink for portability"), \
 215      readlink (f, b, s))
 216 #endif
 217
 218
 219 #if @GNULIB_SLEEP@
 220 /* Pause the execution of the current thread for N seconds.
 221    Returns the number of seconds left to sleep.
 222    See the POSIX:2001 specification
 223    <http://www.opengroup.org/susv3xsh/sleep.html>.  */
 224 # if !@HAVE_SLEEP@
 225 extern unsigned int sleep (unsigned int n);
 226 # endif
 227 #elif defined GNULIB_POSIXCHECK
 228 # undef sleep
 229 # define sleep(n) \
 230     (GL_LINK_WARNING ("sleep is unportable - " \
 231                       "use gnulib module sleep for portability"), \
 232      sleep (n))
 233 #endif
 234
 235
 236 #ifdef __cplusplus
 237 }
 238 #endif
 239
 240
 241 #endif /* _GL_UNISTD_H */
 242 #endif /* _GL_UNISTD_H */