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57 lines
2.2 KiB
Plaintext
57 lines
2.2 KiB
Plaintext
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This is GNU cpio, a program to manage archives of files.
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As of version 2.0, it supports the features of the System V release 4
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cpio, including support for tar archives.
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The main advantages of GNU cpio over Unix versions are:
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* It can access tape drives on other hosts using TCP/IP.
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* `-o' and `-p' can copy symbolic links either as symbolic links or,
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with `-L', as the files they point to.
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* `-i' automatically recognizes the archive format and tries to
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recover from corrupted archives.
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* The output of '-itv' looks like 'ls -l'.
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* It accepts long-named options as well as traditional
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single-character options.
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A few features of other versions of cpio are missing from GNU cpio, including:
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* The `-6' option to support Sixth Edition Unix cpio archives with `-i'.
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* An option to limit volume size, like afio -s.
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GNU cpio supports the POSIX.1 "ustar" tar format. GNU tar supports a
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somewhat different, early draft of that format. That draft format has
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a slightly different magic number in the tar header and doesn't
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include the path prefix part of the header, which allows storing file
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names that are longer than 100 characters. GNU cpio knows to
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recognize the nonstandard GNU tar "ustar" archives.
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The following patch to GNU tar 1.11.1 makes GNU tar recognize standard
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"ustar" archives, such as GNU cpio produces, except that it won't use
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the path prefix. Without this patch, GNU tar thinks that standard
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"ustar" archives are old-format tar archives and can not use the extra
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information that "ustar" format contains. If you use this patch,
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remember that you will lose the beginnings of paths that are longer
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than 100 characters. That's why it's not an official part of GNU tar.
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(Adding support for the path prefix to GNU tar is not trivial.)
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--- list.c.orig Mon Sep 14 17:04:03 1992
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+++ list.c Wed Oct 14 14:02:28 1992
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@@ -439,7 +439,7 @@
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st->st_ctime = from_oct(1+12, header->header.ctime);
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}
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- if (0==strcmp(header->header.magic, TMAGIC)) {
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+ if (0==strncmp(header->header.magic, TMAGIC, 5)) {
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/* Unix Standard tar archive */
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*stdp = 1;
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if (wantug) {
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Mail suggestions and bug reports for GNU cpio to
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bug-gnu-utils@prep.ai.mit.edu.
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