sysdeps/unix/sysv/linux/lddlibc4.c

   1 /* Stub for ldd script to print Linux libc4 dependencies.
   2    Copyright (C) 1998-2017 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, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 /* This code is based on the `ldd' program code from the Linux ld.so
  21    package.  */
  22
  23 #include <a.out.h>
  24 #include <errno.h>
  25 #include <error.h>
  26 #include <libintl.h>
  27 #include <locale.h>
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <unistd.h>
  32
  33 /* Get libc version number.  */
  34 #include "../version.h"
  35
  36 #define PACKAGE _libc_intl_domainname
  37
  38
  39 int
  40 main (int argc, char *argv[])
  41 {
  42   const char *filename;
  43   size_t filename_len;
  44   struct exec exec;
  45   char *buf;
  46   FILE *fp;
  47
  48   /* Set locale via LC_ALL.  */
  49   setlocale (LC_ALL, "");
  50
  51   /* Set the text message domain.  */
  52   textdomain (PACKAGE);
  53
  54   /* We expect exactly one argument.  */
  55   if (argc != 2)
  56     return 1;
  57
  58   if (strcmp (argv[1], "--help") == 0)
  59     {
  60       printf (gettext ("Usage: lddlibc4 FILE\n\n"));
  61       printf (gettext ("For bug reporting instructions, please see:\n\
  62 %s.\n"), REPORT_BUGS_TO);
  63       return 0;
  64     }
  65   else if (strcmp (argv[1], "--version") == 0)
  66     {
  67       printf ("lddlibc4 %s%s\n", PKGVERSION, VERSION);
  68       printf (gettext ("\
  69 Copyright (C) %s Free Software Foundation, Inc.\n\
  70 This is free software; see the source for copying conditions.  There is NO\n\
  71 warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\
  72 "), "2017");
  73       return 0;
  74     }
  75
  76   filename = argv[1];
  77
  78   /* First see whether this is really an a.out binary.  */
  79   fp = fopen (filename, "rb");
  80   if (fp == NULL)
  81     error (2, errno, gettext ("cannot open `%s'"), filename);
  82
  83   /* Read the program header.  */
  84   if (fread (&exec, sizeof exec, 1, fp) < 1)
  85     error (2, errno, gettext ("cannot read header from `%s'"), filename);
  86
  87   /* Test for the magic numbers.  */
  88   if (N_MAGIC (exec) != ZMAGIC && N_MAGIC (exec) != QMAGIC
  89       && N_MAGIC (exec) != OMAGIC)
  90     exit (3);
  91
  92   /* We don't need the file open anymore.  */
  93   fclose (fp);
  94
  95   /* We must put `__LDD_ARGV0=<program-name>' in the environment.  */
  96   filename_len = strlen (filename);
  97   buf = (char *) alloca (sizeof "__LDD_ARGV0=" + filename_len);
  98   mempcpy (mempcpy (buf, "__LDD_ARGV0=", sizeof "__LDD_ARGV0=" - 1),
  99            filename, filename_len + 1);
 100   /* ...and put the value in the environment.  */
 101   putenv (buf);
 102
 103   /* Now we can execute the binary.  */
 104   return execv (filename, &argv[argc]) ? 4 : 0;
 105 }