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
39 int
main(int argc,char * argv[])40 main (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 ("\
100 Failed 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