elf/dl-origin.c

   1 /* Find path of executable.
   2    Copyright (C) 1998, 1999, 2000, 2002, 2004 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <sys/param.h>
  24 #include <ldsodefs.h>
  25
  26 #include <dl-dst.h>
  27
  28
  29 const char *
  30 _dl_get_origin (void)
  31 {
  32   char *result = (char *) -1;
  33   /* We use the environment variable LD_ORIGIN_PATH.  If it is set make
  34      a copy and strip out trailing slashes.  */
  35   if (GLRO(dl_origin_path) != NULL)
  36     {
  37       size_t len = strlen (GLRO(dl_origin_path));
  38       result = (char *) malloc (len + 1);
  39       if (result == NULL)
  40         result = (char *) -1;
  41       else
  42         {
  43           char *cp = __mempcpy (result, GLRO(dl_origin_path), len);
  44           while (cp > result + 1 && cp[-1] == '/')
  45             --cp;
  46           *cp = '\0';
  47         }
  48     }
  49
  50   return result;
  51 }