gnu/dist/gettext/gettext-tools/lib/xgetcwd.c

   1 /* xgetcwd.c -- return current directory with unlimited length
   2    Copyright (C) 1992, 1996, 2000, 2003 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  17
  18 /* Written by David MacKenzie <djm@gnu.ai.mit.edu>.  */
  19
  20 #if HAVE_CONFIG_H
  21 # include <config.h>
  22 #endif
  23
  24 #include <stdlib.h>
  25 #include <stdio.h>
  26 #include <errno.h>
  27 #ifndef errno
  28 extern int errno;
  29 #endif
  30
  31 #include <sys/types.h>
  32 #if HAVE_UNISTD_H
  33 # include <unistd.h>
  34 #endif
  35
  36 #include "pathmax.h"
  37
  38 #if HAVE_GETCWD
  39 # ifdef VMS
  40    /* We want the directory in Unix syntax, not in VMS syntax.  */
  41 #  define getcwd(Buf, Max) (getcwd) (Buf, Max, 0)
  42 # else
  43 #  ifndef _FORTIFY_SOURCE
  44 char *getcwd ();
  45 #  endif
  46 # endif
  47 #else
  48 char *getwd ();
  49 # define getcwd(Buf, Max) getwd (Buf)
  50 #endif
  51
  52 #include "xalloc.h"
  53
  54 /* Return the current directory, newly allocated, arbitrarily long.
  55    Return NULL and set errno on error. */
  56
  57 char *
  58 xgetcwd ()
  59 {
  60   char *ret;
  61   unsigned path_max;
  62   char buf[1024];
  63
  64   errno = 0;
  65   ret = getcwd (buf, sizeof (buf));
  66   if (ret != NULL)
  67     return xstrdup (buf);
  68   if (errno != ERANGE)
  69     return NULL;
  70
  71   path_max = (unsigned) PATH_MAX;
  72   path_max += 2;                /* The getcwd docs say to do this. */
  73
  74   for (;;)
  75     {
  76       char *cwd = (char *) xmalloc (path_max);
  77
  78       errno = 0;
  79       ret = getcwd (cwd, path_max);
  80       if (ret != NULL)
  81         return ret;
  82       if (errno != ERANGE)
  83         {
  84           int save_errno = errno;
  85           free (cwd);
  86           errno = save_errno;
  87           return NULL;
  88         }
  89
  90       free (cwd);
  91
  92       path_max += path_max / 16;
  93       path_max += 32;
  94     }
  95 }