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 # @INCLUDE_NEXT@ @NEXT_UNISTD_H@
  23 #endif
  24
  25 #ifndef _GL_UNISTD_H
  26 #define _GL_UNISTD_H
  27
  28 /* mingw doesn't define the SEEK_* macros in <unistd.h>.  */
  29 #if !(defined SEEK_CUR && defined SEEK_END && defined SEEK_SET)
  30 # include <stdio.h>
  31 #endif
  32
  33 /* mingw fails to declare _exit in <unistd.h>.  */
  34 #include <stdlib.h>
  35
  36 /* The definition of GL_LINK_WARNING is copied here.  */
  37
  38
  39 /* Declare overridden functions.  */
  40
  41 #ifdef __cplusplus
  42 extern "C" {
  43 #endif
  44
  45
  46 #if @GNULIB_CHOWN@
  47 # if @REPLACE_CHOWN@
  48 #  ifndef REPLACE_CHOWN
  49 #   define REPLACE_CHOWN 1
  50 #  endif
  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).  Follow symbolic links.
  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 # endif
  61 #elif defined GNULIB_POSIXCHECK
  62 # undef chown
  63 # define chown(f,u,g) \
  64     (GL_LINK_WARNING ("chown fails to follow symlinks on some systems and " \
  65                       "doesn't treat a uid or gid of -1 on some systems - " \
  66                       "use gnulib module chown for portability"), \
  67      chown (f, u, g))
  68 #endif
  69
  70
  71 #if @GNULIB_DUP2@
  72 # if !@HAVE_DUP2@
  73 /* Copy the file descriptor OLDFD into file descriptor NEWFD.  Do nothing if
  74    NEWFD = OLDFD, otherwise close NEWFD first if it is open.
  75    Return 0 if successful, otherwise -1 and errno set.
  76    See the POSIX:2001 specification
  77    <http://www.opengroup.org/susv3xsh/dup2.html>.  */
  78 extern int dup2 (int oldfd, int newfd);
  79 # endif
  80 #elif defined GNULIB_POSIXCHECK
  81 # undef dup2
  82 # define dup2(o,n) \
  83     (GL_LINK_WARNING ("dup2 is unportable - " \
  84                       "use gnulib module dup2 for portability"), \
  85      dup2 (o, n))
  86 #endif
  87
  88
  89 #if @GNULIB_FCHDIR@
  90 # if @REPLACE_FCHDIR@
  91
  92 /* Change the process' current working directory to the directory on which
  93    the given file descriptor is open.
  94    Return 0 if successful, otherwise -1 and errno set.
  95    See the POSIX:2001 specification
  96    <http://www.opengroup.org/susv3xsh/fchdir.html>.  */
  97 extern int fchdir (int /*fd*/);
  98
  99 #  define close rpl_close
 100 extern int close (int);
 101 #  define dup rpl_dup
 102 extern int dup (int);
 103 #  define dup2 rpl_dup2
 104 extern int dup2 (int, int);
 105
 106 # endif
 107 #elif defined GNULIB_POSIXCHECK
 108 # undef fchdir
 109 # define fchdir(f) \
 110     (GL_LINK_WARNING ("fchdir is unportable - " \
 111                       "use gnulib module fchdir for portability"), \
 112      fchdir (f))
 113 #endif
 114
 115
 116 #if @GNULIB_FTRUNCATE@
 117 # if !@HAVE_FTRUNCATE@
 118 /* Change the size of the file to which FD is opened to become equal to LENGTH.
 119    Return 0 if successful, otherwise -1 and errno set.
 120    See the POSIX:2001 specification
 121    <http://www.opengroup.org/susv3xsh/ftruncate.html>.  */
 122 extern int ftruncate (int fd, off_t length);
 123 # endif
 124 #elif defined GNULIB_POSIXCHECK
 125 # undef ftruncate
 126 # define ftruncate(f,l) \
 127     (GL_LINK_WARNING ("ftruncate is unportable - " \
 128                       "use gnulib module ftruncate for portability"), \
 129      ftruncate (f, l))
 130 #endif
 131
 132
 133 #if @GNULIB_GETCWD@
 134 /* Include the headers that might declare getcwd so that they will not
 135    cause confusion if included after this file.  */
 136 # include <stdlib.h>
 137 # if @REPLACE_GETCWD@
 138 /* Get the name of the current working directory, and put it in SIZE bytes
 139    of BUF.
 140    Return BUF if successful, or NULL if the directory couldn't be determined
 141    or SIZE was too small.
 142    See the POSIX:2001 specification
 143    <http://www.opengroup.org/susv3xsh/getcwd.html>.
 144    Additionally, the gnulib module 'getcwd' guarantees the following GNU
 145    extension: If BUF is NULL, an array is allocated with 'malloc'; the array
 146    is SIZE bytes long, unless SIZE == 0, in which case it is as big as
 147    necessary.  */
 148 #  define getcwd rpl_getcwd
 149 extern char * getcwd (char *buf, size_t size);
 150 # endif
 151 #elif defined GNULIB_POSIXCHECK
 152 # undef getcwd
 153 # define getcwd(b,s) \
 154     (GL_LINK_WARNING ("getcwd is unportable - " \
 155                       "use gnulib module getcwd for portability"), \
 156      getcwd (b, s))
 157 #endif
 158
 159
 160 #if @GNULIB_GETLOGIN_R@
 161 /* Copies the user's login name to NAME.
 162    The array pointed to by NAME has room for SIZE bytes.
 163
 164    Returns 0 if successful.  Upon error, an error number is returned, or -1 in
 165    the case that the login name cannot be found but no specific error is
 166    provided (this case is hopefully rare but is left open by the POSIX spec).
 167
 168    See <http://www.opengroup.org/susv3xsh/getlogin.html>.
 169  */
 170 # if !@HAVE_DECL_GETLOGIN_R@
 171 #  include <stddef.h>
 172 extern int getlogin_r (char *name, size_t size);
 173 # endif
 174 #elif defined GNULIB_POSIXCHECK
 175 # undef getlogin_r
 176 # define getlogin_r(n,s) \
 177     (GL_LINK_WARNING ("getlogin_r is unportable - " \
 178                       "use gnulib module getlogin_r for portability"), \
 179      getlogin_r (n, s))
 180 #endif
 181
 182
 183 #if @GNULIB_LCHOWN@
 184 # if @REPLACE_LCHOWN@
 185 /* Change the owner of FILE to UID (if UID is not -1) and the group of FILE
 186    to GID (if GID is not -1).  Do not follow symbolic links.
 187    Return 0 if successful, otherwise -1 and errno set.
 188    See the POSIX:2001 specification
 189    <http://www.opengroup.org/susv3xsh/lchown.html>.  */
 190 #  define lchown rpl_lchown
 191 extern int lchown (char const *file, uid_t owner, gid_t group);
 192 # endif
 193 #elif defined GNULIB_POSIXCHECK
 194 # undef lchown
 195 # define lchown(f,u,g) \
 196     (GL_LINK_WARNING ("lchown is unportable to pre-POSIX.1-2001 " \
 197                       "systems - use gnulib module lchown for portability"), \
 198      lchown (f, u, g))
 199 #endif
 200
 201
 202 #if @GNULIB_LSEEK@
 203 # if @REPLACE_LSEEK@
 204 /* Set the offset of FD relative to SEEK_SET, SEEK_CUR, or SEEK_END.
 205    Return the new offset if successful, otherwise -1 and errno set.
 206    See the POSIX:2001 specification
 207    <http://www.opengroup.org/susv3xsh/lseek.html>.  */
 208 #  define lseek rpl_lseek
 209    extern off_t lseek (int fd, off_t offset, int whence);
 210 # endif
 211 #elif defined GNULIB_POSIXCHECK
 212 # undef lseek
 213 # define lseek(f,o,w) \
 214     (GL_LINK_WARNING ("lseek does not fail with ESPIPE on pipes on some " \
 215                       "systems - use gnulib module lseek for portability"), \
 216      lseek (f, o, w))
 217 #endif
 218
 219
 220 #if @GNULIB_READLINK@
 221 /* Read the contents of the symbolic link FILE and place the first BUFSIZE
 222    bytes of it into BUF.  Return the number of bytes placed into BUF if
 223    successful, otherwise -1 and errno set.
 224    See the POSIX:2001 specification
 225    <http://www.opengroup.org/susv3xsh/readlink.html>.  */
 226 # if !@HAVE_READLINK@
 227 #  include <stddef.h>
 228 extern int readlink (const char *file, char *buf, size_t bufsize);
 229 # endif
 230 #elif defined GNULIB_POSIXCHECK
 231 # undef readlink
 232 # define readlink(f,b,s) \
 233     (GL_LINK_WARNING ("readlink is unportable - " \
 234                       "use gnulib module readlink for portability"), \
 235      readlink (f, b, s))
 236 #endif
 237
 238
 239 #if @GNULIB_SLEEP@
 240 /* Pause the execution of the current thread for N seconds.
 241    Returns the number of seconds left to sleep.
 242    See the POSIX:2001 specification
 243    <http://www.opengroup.org/susv3xsh/sleep.html>.  */
 244 # if !@HAVE_SLEEP@
 245 extern unsigned int sleep (unsigned int n);
 246 # endif
 247 #elif defined GNULIB_POSIXCHECK
 248 # undef sleep
 249 # define sleep(n) \
 250     (GL_LINK_WARNING ("sleep is unportable - " \
 251                       "use gnulib module sleep for portability"), \
 252      sleep (n))
 253 #endif
 254
 255
 256 #ifdef __cplusplus
 257 }
 258 #endif
 259
 260
 261 #endif /* _GL_UNISTD_H */
 262 #endif /* _GL_UNISTD_H */