1/* Copyright (C) 1999, 2000, 2002 Red Hat, Inc.
2   This file is part of Red Hat elfutils.
3   Written by Ulrich Drepper <drepper@redhat.com>, 1999.
4
5   Red Hat elfutils is free software; you can redistribute it and/or modify
6   it under the terms of the GNU General Public License as published by the
7   Free Software Foundation; version 2 of the License.
8
9   Red Hat elfutils is distributed in the hope that it will be useful, but
10   WITHOUT ANY WARRANTY; without even the implied warranty of
11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12   General Public License for more details.
13
14   You should have received a copy of the GNU General Public License along
15   with Red Hat elfutils; if not, write to the Free Software Foundation,
16   Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
17
18   Red Hat elfutils is an included package of the Open Invention Network.
19   An included package of the Open Invention Network is a package for which
20   Open Invention Network licensees cross-license their patents.  No patent
21   license is granted, either expressly or impliedly, by designation as an
22   included package.  Should you wish to participate in the Open Invention
23   Network licensing program, please visit www.openinventionnetwork.com
24   <http://www.openinventionnetwork.com>.  */
25
26#ifdef HAVE_CONFIG_H
27# include <config.h>
28#endif
29
30#include <fcntl.h>
31#include <gelf.h>
32#include <stdio.h>
33#include <stdlib.h>
34#include <string.h>
35#include <unistd.h>
36#include <sys/param.h>
37
38
39int
40main (int argc, char *argv[])
41{
42  int fd;
43  Elf *elf;
44  Elf *subelf;
45  Elf_Cmd cmd;
46  off_t offset;
47  size_t todo;
48
49  if (argc < 4)
50    exit (1);
51
52  /* Open the archive.  */
53  fd = open (argv[1], O_RDONLY);
54  if (fd == -1)
55    {
56      printf ("Cannot open input file: %m");
57      exit (1);
58    }
59
60  /* Set the ELF version.  */
61  elf_version (EV_CURRENT);
62
63  /* Create an ELF descriptor.  */
64  cmd = ELF_C_READ;
65  elf = elf_begin (fd, cmd, NULL);
66  if (elf == NULL)
67    {
68      printf ("Cannot create ELF descriptor: %s\n", elf_errmsg (-1));
69      exit (1);
70    }
71
72  /* If it is no archive punt.  */
73  if (elf_kind (elf) != ELF_K_AR)
74    {
75      printf ("`%s' is no archive\n", argv[1]);
76      exit (1);
77    }
78
79  /* Get the elements of the archive one after the other.  */
80  while ((subelf = elf_begin (fd, cmd, elf)) != NULL)
81    {
82      /* The the header for this element.  */
83      Elf_Arhdr *arhdr = elf_getarhdr (subelf);
84
85      if (arhdr == NULL)
86	{
87	  printf ("cannot get arhdr: %s\n", elf_errmsg (-1));
88	  exit (1);
89	}
90
91      if (strcmp (arhdr->ar_name, argv[2]) == 0)
92	{
93	  int outfd;
94
95	  /* Get the offset of the file in the archive.  */
96	  offset = elf_getbase (subelf);
97	  if (offset == -1)
98	    {
99	      printf ("\
100Failed to get base address for the archive element: %s\n",
101		      elf_errmsg (-1));
102	      exit (1);
103	    }
104
105	  /* Open the output file.  */
106	  outfd = open (argv[3], O_CREAT | O_TRUNC | O_RDWR, 0666);
107	  if (outfd == -1)
108	    {
109	      printf ("cannot open output file: %m");
110	      exit (1);
111	    }
112
113	  /* Now write out the data.  */
114	  todo = arhdr->ar_size;
115	  while (todo > 0)
116	    {
117	      char buf[1024];
118	      ssize_t n = pread (fd, buf, MIN (sizeof buf, todo), offset);
119	      if (n == 0)
120		break;
121
122	      if (write (outfd, buf, n) != n)
123		{
124		  puts ("Writing output failed");
125		  exit (1);
126		}
127
128	      offset += n;
129	      todo -= n;
130	    }
131
132	  /* Check whether all the date was read and written out.  */
133	  if (todo != 0)
134	    {
135	      puts ("Reading archive member failed.");
136	      exit (1);
137	    }
138
139	  /* Close the descriptors.  */
140	  if (elf_end (subelf) != 0 || elf_end (elf) != 0)
141	    {
142	      printf ("Freeing ELF descriptors failed: %s", elf_errmsg (-1));
143	      exit (1);
144	    }
145
146	  close (outfd);
147	  close (fd);
148
149	  /* All went well.  */
150	  exit (0);
151	}
152
153      /* Get next archive element.  */
154      cmd = elf_next (subelf);
155      if (elf_end (subelf) != 0)
156	{
157	  printf ("error while freeing sub-ELF descriptor: %s\n",
158		  elf_errmsg (-1));
159	  exit (1);
160	}
161    }
162
163  /* When we reach this point we haven't found the given file in the
164     archive.  */
165  printf ("File `%s' not found in archive\n", argv[2]);
166  exit (1);
167}
168