gl/unistd.in.h

   1 /* Substitute for and wrapper around <unistd.h>.
   2    Copyright (C) 2004-2008 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 3, 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 #if @GNULIB_GETHOSTNAME@
 160 # if !@HAVE_DECL_GETHOSTNAME@
 161 #  include <stddef.h>
 162   extern int gethostname (char *name, size_t size);
 163 # endif
 164 #elif defined GNULIB_POSIXCHECK
 165 # undef gethostname
 166 # define gethostname(n,s)                           \
 167   (GL_LINK_WARNING ("gethostname is unportable - "                     \
 168                     "use gnulib module gethostname for portability"),   \
 169    gethostname (n, s))
 170 #endif
 171
 172 #if @GNULIB_GETLOGIN_R@
 173 /* Copies the user's login name to NAME.
 174    The array pointed to by NAME has room for SIZE bytes.
 175
 176    Returns 0 if successful.  Upon error, an error number is returned, or -1 in
 177    the case that the login name cannot be found but no specific error is
 178    provided (this case is hopefully rare but is left open by the POSIX spec).
 179
 180    See <http://www.opengroup.org/susv3xsh/getlogin.html>.
 181  */
 182 # if !@HAVE_DECL_GETLOGIN_R@
 183 #  include <stddef.h>
 184 extern int getlogin_r (char *name, size_t size);
 185 # endif
 186 #elif defined GNULIB_POSIXCHECK
 187 # undef getlogin_r
 188 # define getlogin_r(n,s) \
 189     (GL_LINK_WARNING ("getlogin_r is unportable - " \
 190                       "use gnulib module getlogin_r for portability"), \
 191      getlogin_r (n, s))
 192 #endif
 193
 194
 195 #if @GNULIB_GETPAGESIZE@
 196 # if @REPLACE_GETPAGESIZE@
 197 #  define getpagesize rpl_getpagesize
 198 extern int getpagesize (void);
 199 # elif !@HAVE_GETPAGESIZE@
 200 /* This is for POSIX systems.  */
 201 #  if !defined getpagesize && defined _SC_PAGESIZE
 202 #   if ! (defined __VMS && __VMS_VER < 70000000)
 203 #    define getpagesize() sysconf (_SC_PAGESIZE)
 204 #   endif
 205 #  endif
 206 /* This is for older VMS.  */
 207 #  if !defined getpagesize && defined __VMS
 208 #   ifdef __ALPHA
 209 #    define getpagesize() 8192
 210 #   else
 211 #    define getpagesize() 512
 212 #   endif
 213 #  endif
 214 /* This is for BeOS.  */
 215 #  if !defined getpagesize && @HAVE_OS_H@
 216 #   include <OS.h>
 217 #   if defined B_PAGE_SIZE
 218 #    define getpagesize() B_PAGE_SIZE
 219 #   endif
 220 #  endif
 221 /* This is for AmigaOS4.0.  */
 222 #  if !defined getpagesize && defined __amigaos4__
 223 #   define getpagesize() 2048
 224 #  endif
 225 /* This is for older Unix systems.  */
 226 #  if !defined getpagesize && @HAVE_SYS_PARAM_H@
 227 #   include <sys/param.h>
 228 #   ifdef EXEC_PAGESIZE
 229 #    define getpagesize() EXEC_PAGESIZE
 230 #   else
 231 #    ifdef NBPG
 232 #     ifndef CLSIZE
 233 #      define CLSIZE 1
 234 #     endif
 235 #     define getpagesize() (NBPG * CLSIZE)
 236 #    else
 237 #     ifdef NBPC
 238 #      define getpagesize() NBPC
 239 #     endif
 240 #    endif
 241 #   endif
 242 #  endif
 243 # endif
 244 #elif defined GNULIB_POSIXCHECK
 245 # undef getpagesize
 246 # define getpagesize() \
 247     (GL_LINK_WARNING ("getpagesize is unportable - " \
 248                       "use gnulib module getpagesize for portability"), \
 249      getpagesize ())
 250 #endif
 251
 252
 253 #if @GNULIB_LCHOWN@
 254 # if @REPLACE_LCHOWN@
 255 /* Change the owner of FILE to UID (if UID is not -1) and the group of FILE
 256    to GID (if GID is not -1).  Do not follow symbolic links.
 257    Return 0 if successful, otherwise -1 and errno set.
 258    See the POSIX:2001 specification
 259    <http://www.opengroup.org/susv3xsh/lchown.html>.  */
 260 #  define lchown rpl_lchown
 261 extern int lchown (char const *file, uid_t owner, gid_t group);
 262 # endif
 263 #elif defined GNULIB_POSIXCHECK
 264 # undef lchown
 265 # define lchown(f,u,g) \
 266     (GL_LINK_WARNING ("lchown is unportable to pre-POSIX.1-2001 " \
 267                       "systems - use gnulib module lchown for portability"), \
 268      lchown (f, u, g))
 269 #endif
 270
 271
 272 #if @GNULIB_LSEEK@
 273 # if @REPLACE_LSEEK@
 274 /* Set the offset of FD relative to SEEK_SET, SEEK_CUR, or SEEK_END.
 275    Return the new offset if successful, otherwise -1 and errno set.
 276    See the POSIX:2001 specification
 277    <http://www.opengroup.org/susv3xsh/lseek.html>.  */
 278 #  define lseek rpl_lseek
 279    extern off_t lseek (int fd, off_t offset, int whence);
 280 # endif
 281 #elif defined GNULIB_POSIXCHECK
 282 # undef lseek
 283 # define lseek(f,o,w) \
 284     (GL_LINK_WARNING ("lseek does not fail with ESPIPE on pipes on some " \
 285                       "systems - use gnulib module lseek for portability"), \
 286      lseek (f, o, w))
 287 #endif
 288
 289
 290 #if @GNULIB_READLINK@
 291 /* Read the contents of the symbolic link FILE and place the first BUFSIZE
 292    bytes of it into BUF.  Return the number of bytes placed into BUF if
 293    successful, otherwise -1 and errno set.
 294    See the POSIX:2001 specification
 295    <http://www.opengroup.org/susv3xsh/readlink.html>.  */
 296 # if !@HAVE_READLINK@
 297 #  include <stddef.h>
 298 extern int readlink (const char *file, char *buf, size_t bufsize);
 299 # endif
 300 #elif defined GNULIB_POSIXCHECK
 301 # undef readlink
 302 # define readlink(f,b,s) \
 303     (GL_LINK_WARNING ("readlink is unportable - " \
 304                       "use gnulib module readlink for portability"), \
 305      readlink (f, b, s))
 306 #endif
 307
 308
 309 #if @GNULIB_SLEEP@
 310 /* Pause the execution of the current thread for N seconds.
 311    Returns the number of seconds left to sleep.
 312    See the POSIX:2001 specification
 313    <http://www.opengroup.org/susv3xsh/sleep.html>.  */
 314 # if !@HAVE_SLEEP@
 315 extern unsigned int sleep (unsigned int n);
 316 # endif
 317 #elif defined GNULIB_POSIXCHECK
 318 # undef sleep
 319 # define sleep(n) \
 320     (GL_LINK_WARNING ("sleep is unportable - " \
 321                       "use gnulib module sleep for portability"), \
 322      sleep (n))
 323 #endif
 324
 325
 326 #ifdef __cplusplus
 327 }
 328 #endif
 329
 330
 331 #endif /* _GL_UNISTD_H */
 332 #endif /* _GL_UNISTD_H */