elf/dl-origin.c

   1 /* Find path of executable.
   2    Copyright (C) 1998-2022 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    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <stdlib.h>
  20 #include <string.h>
  21 #include <sys/param.h>
  22 #include <ldsodefs.h>
  23
  24 #include <dl-dst.h>
  25
  26
  27 const char *
  28 _dl_get_origin (void)
  29 {
  30   char *result = (char *) -1;
  31   /* We use the environment variable LD_ORIGIN_PATH.  If it is set make
  32      a copy and strip out trailing slashes.  */
  33   if (GLRO(dl_origin_path) != NULL)
  34     {
  35       size_t len = strlen (GLRO(dl_origin_path));
  36       result = (char *) malloc (len + 1);
  37       if (result == NULL)
  38         result = (char *) -1;
  39       else
  40         {
  41           char *cp = __mempcpy (result, GLRO(dl_origin_path), len);
  42           while (cp > result + 1 && cp[-1] == '/')
  43             --cp;
  44           *cp = '\0';
  45         }
  46     }
  47
  48   return result;
  49 }