gl/progname.c

   1 /* Program name management.
   2    Copyright (C) 2001-2003, 2005-2009 Free Software Foundation, Inc.
   3    Written by Bruno Haible <haible@clisp.cons.org>, 2001.
   4
   5    This program is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program 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
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  17
  18
  19 #include <config.h>
  20
  21 /* Specification.  */
  22 #undef ENABLE_RELOCATABLE /* avoid defining set_program_name as a macro */
  23 #include "progname.h"
  24
  25 #include <errno.h> /* get program_invocation_name declaration */
  26 #include <string.h>
  27
  28
  29 /* String containing name the program is called with.
  30    To be initialized by main().  */
  31 const char *program_name = NULL;
  32
  33 /* Set program_name, based on argv[0].  */
  34 void
  35 set_program_name (const char *argv0)
  36 {
  37   /* libtool creates a temporary executable whose name is sometimes prefixed
  38      with "lt-" (depends on the platform).  It also makes argv[0] absolute.
  39      But the name of the temporary executable is a detail that should not be
  40      visible to the end user and to the test suite.
  41      Remove this "<dirname>/.libs/" or "<dirname>/.libs/lt-" prefix here.  */
  42   const char *slash;
  43   const char *base;
  44
  45   slash = strrchr (argv0, '/');
  46   base = (slash != NULL ? slash + 1 : argv0);
  47   if (base - argv0 >= 7 && strncmp (base - 7, "/.libs/", 7) == 0)
  48     {
  49       argv0 = base;
  50       if (strncmp (base, "lt-", 3) == 0)
  51         {
  52           argv0 = base + 3;
  53           /* On glibc systems, remove the "lt-" prefix from the variable
  54              program_invocation_short_name.  */
  55 #if HAVE_DECL_PROGRAM_INVOCATION_SHORT_NAME
  56           program_invocation_short_name = (char *) argv0;
  57 #endif
  58         }
  59     }
  60
  61   /* But don't strip off a leading <dirname>/ in general, because when the user
  62      runs
  63          /some/hidden/place/bin/cp foo foo
  64      he should get the error message
  65          /some/hidden/place/bin/cp: `foo' and `foo' are the same file
  66      not
  67          cp: `foo' and `foo' are the same file
  68    */
  69
  70   program_name = argv0;
  71
  72   /* On glibc systems, the error() function comes from libc and uses the
  73      variable program_invocation_name, not program_name.  So set this variable
  74      as well.  */
  75 #if HAVE_DECL_PROGRAM_INVOCATION_NAME
  76   program_invocation_name = (char *) argv0;
  77 #endif
  78 }