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Diffstat (limited to 'gnu/usr.bin/cpio/README')
-rw-r--r-- | gnu/usr.bin/cpio/README | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/gnu/usr.bin/cpio/README b/gnu/usr.bin/cpio/README new file mode 100644 index 0000000..83b5228 --- /dev/null +++ b/gnu/usr.bin/cpio/README @@ -0,0 +1,56 @@ +This is GNU cpio, a program to manage archives of files. +As of version 2.0, it supports the features of the System V release 4 +cpio, including support for tar archives. + +The main advantages of GNU cpio over Unix versions are: + +* It can access tape drives on other hosts using TCP/IP. + +* `-o' and `-p' can copy symbolic links either as symbolic links or, +with `-L', as the files they point to. + +* `-i' automatically recognizes the archive format and tries to +recover from corrupted archives. + +* The output of '-itv' looks like 'ls -l'. + +* It accepts long-named options as well as traditional +single-character options. + +A few features of other versions of cpio are missing from GNU cpio, including: + +* The `-6' option to support Sixth Edition Unix cpio archives with `-i'. + +* An option to limit volume size, like afio -s. + + +GNU cpio supports the POSIX.1 "ustar" tar format. GNU tar supports a +somewhat different, early draft of that format. That draft format has +a slightly different magic number in the tar header and doesn't +include the path prefix part of the header, which allows storing file +names that are longer than 100 characters. GNU cpio knows to +recognize the nonstandard GNU tar "ustar" archives. + +The following patch to GNU tar 1.11.1 makes GNU tar recognize standard +"ustar" archives, such as GNU cpio produces, except that it won't use +the path prefix. Without this patch, GNU tar thinks that standard +"ustar" archives are old-format tar archives and can not use the extra +information that "ustar" format contains. If you use this patch, +remember that you will lose the beginnings of paths that are longer +than 100 characters. That's why it's not an official part of GNU tar. +(Adding support for the path prefix to GNU tar is not trivial.) + +--- list.c.orig Mon Sep 14 17:04:03 1992 ++++ list.c Wed Oct 14 14:02:28 1992 +@@ -439,7 +439,7 @@ + st->st_ctime = from_oct(1+12, header->header.ctime); + } + +- if (0==strcmp(header->header.magic, TMAGIC)) { ++ if (0==strncmp(header->header.magic, TMAGIC, 5)) { + /* Unix Standard tar archive */ + *stdp = 1; + if (wantug) { + +Mail suggestions and bug reports for GNU cpio to +bug-gnu-utils@prep.ai.mit.edu. |