io/getwd.c

   1 /* Obsolete function to get current working directory.
   2    Copyright (C) 1991-2017 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <limits.h>
  21 #include <string.h>
  22 #include <unistd.h>
  23
  24
  25 char *
  26 getwd (char *buf)
  27 {
  28 #ifndef PATH_MAX
  29 #define PATH_MAX 1024
  30 #endif
  31   char tmpbuf[PATH_MAX];
  32
  33   if (buf == NULL)
  34     {
  35       __set_errno (EINVAL);
  36       return NULL;
  37     }
  38
  39   if (__getcwd (tmpbuf, PATH_MAX) == NULL)
  40     {
  41       /* We use 1024 here since it should really be enough and because
  42          this is a safe value.  */
  43       __strerror_r (errno, buf, 1024);
  44       return NULL;
  45     }
  46
  47   /* This is completely unsafe.  Nobody can say how big the user
  48      provided buffer is.  Perhaps the application and the libc
  49      disagree about the value of PATH_MAX.  */
  50   return strcpy (buf, tmpbuf);
  51 }
  52
  53 link_warning (getwd,
  54               "the `getwd' function is dangerous and should not be used.")