io/getwd.c

   1 /* Copyright (C) 1991, 1992, 1996 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 <errno.h>
  20 #include <limits.h>
  21 #include <string.h>
  22 #include <unistd.h>
  23
  24 /* Put the absolute pathname of the current working direction in BUF.
  25    If successful, return BUF.  If not, put an error message in
  26    BUF and return NULL.  BUF should be at least PATH_MAX bytes long.  */
  27 char *
  28 getwd (buf)
  29      char *buf;
  30 {
  31 #ifndef PATH_MAX
  32 #define PATH_MAX 1024
  33   char fetchbuf[PATH_MAX];
  34 #else
  35 #define fetchbuf buf
  36 #endif
  37
  38   if (buf == NULL)
  39     {
  40       __set_errno (EINVAL);
  41       return NULL;
  42     }
  43
  44   if (getcwd (fetchbuf, PATH_MAX) == NULL)
  45     {
  46 #if defined HAVE_STRERROR_R || defined _LIBC
  47       __strerror_r (errno, buf, PATH_MAX);
  48 #else
  49       strncpy (buf, strerror (errno), PATH_MAX);
  50 #endif
  51       return NULL;
  52     }
  53
  54   if (fetchbuf != buf)
  55     strcpy (buf, fetchbuf);
  56
  57   return buf;
  58 }