sysdeps/unix/sysv/linux/lddlibc4.c

   1 /* Stub for ldd script to print Linux libc4 dependencies.
   2    Copyright (C) 1998, 2005 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 /* This code is based on the `ldd' program code from the Linux ld.so
  22    package.  */
  23
  24 #include <a.out.h>
  25 #include <errno.h>
  26 #include <error.h>
  27 #include <libintl.h>
  28 #include <locale.h>
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <unistd.h>
  33
  34 /* Get libc version number.  */
  35 #include "../version.h"
  36
  37 #define PACKAGE _libc_intl_domainname
  38
  39
  40 int
  41 main (int argc, char *argv[])
  42 {
  43   const char *filename;
  44   size_t filename_len;
  45   struct exec exec;
  46   char *buf;
  47   FILE *fp;
  48
  49   /* Set locale via LC_ALL.  */
  50   setlocale (LC_ALL, "");
  51
  52   /* Set the text message domain.  */
  53   textdomain (PACKAGE);
  54
  55   /* We expect exactly one argument.  */
  56   if (argc != 2)
  57     return 1;
  58
  59   filename = argv[1];
  60
  61   /* First see whether this is really an a.out binary.  */
  62   fp = fopen (filename, "rb");
  63   if (fp == NULL)
  64     error (2, errno, gettext ("cannot open `%s'"), filename);
  65
  66   /* Read the program header.  */
  67   if (fread (&exec, sizeof exec, 1, fp) < 1)
  68     error (2, errno, gettext ("cannot read header from `%s'"), filename);
  69
  70   /* Test for the magic numbers.  */
  71   if (N_MAGIC (exec) != ZMAGIC && N_MAGIC (exec) != QMAGIC
  72       && N_MAGIC (exec) != OMAGIC)
  73     exit (3);
  74
  75   /* We don't need the file open anymore.  */
  76   fclose (fp);
  77
  78   /* We must put `__LDD_ARGV0=<program-name>' in the environment.  */
  79   filename_len = strlen (filename);
  80   buf = (char *) alloca (sizeof "__LDD_ARGV0=" + filename_len);
  81   mempcpy (mempcpy (buf, "__LDD_ARGV0=", sizeof "__LDD_ARGV0=" - 1),
  82            filename, filename_len + 1);
  83   /* ...and put the value in the environment.  */
  84   putenv (buf);
  85
  86   /* Now we can execute the binary.  */
  87   return execv (filename, &argv[argc]) ? 4 : 0;
  88 }