source: trunk/essentials/app-arch/cpio/README@ 3399

Last change on this file since 3399 was 3332, checked in by bird, 18 years ago

cpio 2.7

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1This is GNU cpio, a program to manage archives of files.
2As of version 2.0, it supports the features of the System V release 4
3cpio, including support for tar archives.
4
5This package also includes rmt, the remote tape server, and mt, a tape
6drive control program; these two programs will only be compiled if
7your system supports remote command execution, and tape drive control
8operations, respectively.
9
10See the file INSTALL for compilation and installation instructions for Unix.
11
12For non-Unix systems [ Note: The non-Unix makefiles have not been tested
13 for this release ]
14
15makefile.pc is a makefile for Turbo C or C++ or Borland C++ on MS-DOS.
16
17makefile.os2 is a makefile for MS C and GNU C (emx/gcc) on OS/2.
18cpio.def is a linker definition file for the MS C OS/2 version.
19
20
21The main advantages of GNU cpio over Unix versions are:
22
23* It can access tape drives on other hosts using TCP/IP.
24
25* `-o' and `-p' can copy symbolic links either as symbolic links or,
26with `-L', as the files they point to.
27
28* `-i' automatically recognizes the archive format and tries to
29recover from corrupted archives.
30
31* The output of '-itv' looks like 'ls -l'.
32
33* It accepts long-named options as well as traditional
34single-character options.
35
36A few features of other versions of cpio are missing from GNU cpio, including:
37
38* The `-6' option to support Sixth Edition Unix cpio archives with `-i'.
39
40* An option to limit volume size, like afio -s.
41
42
43GNU cpio supports the POSIX.1 "ustar" tar format. GNU tar supports a
44somewhat different, early draft of that format. That draft format has
45a slightly different magic number in the tar header and doesn't
46include the path prefix part of the header, which allows storing file
47names that are longer than 100 characters. GNU cpio knows to
48recognize the nonstandard GNU tar "ustar" archives.
49
50The following patch to GNU tar 1.11.1 makes GNU tar recognize standard
51"ustar" archives, such as GNU cpio produces, except that it won't use
52the path prefix. Without this patch, GNU tar thinks that standard
53"ustar" archives are old-format tar archives and can not use the extra
54information that "ustar" format contains. If you use this patch,
55remember that you will lose the beginnings of paths that are longer
56than 100 characters. That's why it's not an official part of GNU tar.
57(Adding support for the path prefix to GNU tar is not trivial.)
58
59--- list.c.orig Mon Sep 14 17:04:03 1992
60+++ list.c Wed Oct 14 14:02:28 1992
61@@ -439,7 +439,7 @@
62 st->st_ctime = from_oct(1+12, header->header.ctime);
63 }
64
65- if (0==strcmp(header->header.magic, TMAGIC)) {
66+ if (0==strncmp(header->header.magic, TMAGIC, 5)) {
67 /* Unix Standard tar archive */
68 *stdp = 1;
69 if (wantug) {
70
71Mail suggestions and bug reports for GNU cpio to bug-cpio@gnu.org.
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