sysdeps/generic/dl-origin.c

   1 /* Find path of executable.
   2    Copyright (C) 1998, 1999, 2000 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 Library General Public License as
   8    published by the Free Software Foundation; either version 2 of the
   9    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    Library General Public License for more details.
  15
  16    You should have received a copy of the GNU Library General Public
  17    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  18    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 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 /* Generally it is not possible to implement this.  We have to fall
  29    back on a solution where the user provides the information.  */
  30 extern const char *_dl_origin_path;
  31
  32 const char *
  33 _dl_get_origin (void)
  34 {
  35   char *result = (char *) -1;
  36   /* We use the environment variable LD_ORIGIN_PATH.  If it is set make
  37      a copy and strip out trailing slashes.  */
  38   if (_dl_origin_path != NULL)
  39     {
  40       size_t len = strlen (_dl_origin_path);
  41       result = malloc (len + 1);
  42       if (result == NULL)
  43         result = (char *) -1;
  44       else
  45         {
  46           char *cp = __mempcpy (result, _dl_origin_path, len);
  47           while (cp > result + 1 && cp[-1] == '/')
  48             --cp;
  49           *cp = '\0';
  50         }
  51     }
  52
  53   return result;
  54 }