1 /* Stub for ldd script to print Linux libc4 dependencies.
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 /* This code is based on the `ldd' program code from the Linux ld.so
20    package.  */
21 
22 #include <a.out.h>
23 #include <errno.h>
24 #include <error.h>
25 #include <libintl.h>
26 #include <locale.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <string.h>
30 #include <unistd.h>
31 
32 /* Get libc version number.  */
33 #include "../version.h"
34 
35 #define PACKAGE _libc_intl_domainname
36 
37 
38 int
main(int argc,char * argv[])39 main (int argc, char *argv[])
40 {
41   const char *filename;
42   size_t filename_len;
43   struct exec exec;
44   char *buf;
45   FILE *fp;
46 
47   /* Set locale via LC_ALL.  */
48   setlocale (LC_ALL, "");
49 
50   /* Set the text message domain.  */
51   textdomain (PACKAGE);
52 
53   /* We expect exactly one argument.  */
54   if (argc != 2)
55     return 1;
56 
57   if (strcmp (argv[1], "--help") == 0)
58     {
59       printf (gettext ("Usage: lddlibc4 FILE\n\n"));
60       printf (gettext ("For bug reporting instructions, please see:\n\
61 %s.\n"), REPORT_BUGS_TO);
62       return 0;
63     }
64   else if (strcmp (argv[1], "--version") == 0)
65     {
66       printf ("lddlibc4 %s%s\n", PKGVERSION, VERSION);
67       printf (gettext ("\
68 Copyright (C) %s Free Software Foundation, Inc.\n\
69 This is free software; see the source for copying conditions.  There is NO\n\
70 warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\
71 "), "2022");
72       return 0;
73     }
74 
75   filename = argv[1];
76 
77   /* First see whether this is really an a.out binary.  */
78   fp = fopen (filename, "rb");
79   if (fp == NULL)
80     error (2, errno, gettext ("cannot open `%s'"), filename);
81 
82   /* Read the program header.  */
83   if (fread (&exec, sizeof exec, 1, fp) < 1)
84     error (2, errno, gettext ("cannot read header from `%s'"), filename);
85 
86   /* Test for the magic numbers.  */
87   if (N_MAGIC (exec) != ZMAGIC && N_MAGIC (exec) != QMAGIC
88       && N_MAGIC (exec) != OMAGIC)
89     exit (3);
90 
91   /* We don't need the file open anymore.  */
92   fclose (fp);
93 
94   /* We must put `__LDD_ARGV0=<program-name>' in the environment.  */
95   filename_len = strlen (filename);
96   buf = (char *) alloca (sizeof "__LDD_ARGV0=" + filename_len);
97   mempcpy (mempcpy (buf, "__LDD_ARGV0=", sizeof "__LDD_ARGV0=" - 1),
98 	   filename, filename_len + 1);
99   /* ...and put the value in the environment.  */
100   putenv (buf);
101 
102   /* Now we can execute the binary.  */
103   return execv (filename, &argv[argc]) ? 4 : 0;
104 }
105