io/getdirname.c

   1 /* Copyright (C) 1992, 1997 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    License, or (at your option) any later version.
   8
   9    The GNU C Library 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 GNU
  12    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 #include <unistd.h>
  20 #include <include/sys/stat.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23
  24 /* Return a malloc'd string containing the current directory name.
  25    If the environment variable `PWD' is set, and its value is correct,
  26    that value is used.  */
  27
  28 char *
  29 get_current_dir_name (void)
  30 {
  31   char *pwd;
  32   struct stat dotstat, pwdstat;
  33
  34   pwd = getenv ("PWD");
  35   if (pwd != NULL &&
  36       stat (".", &dotstat) == 0 &&
  37       stat (pwd, &pwdstat) == 0 &&
  38       pwdstat.st_dev == dotstat.st_dev &&
  39       pwdstat.st_ino == dotstat.st_ino)
  40     /* The PWD value is correct.  Use it.  */
  41     return strdup (pwd);
  42
  43   return getcwd ((char *) NULL, 0);
  44 }