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Path: sserve!manuel!munnari.oz.au!uunet!auspex-gw!guy
From: guy@Auspex.COM (Guy Harris)
Newsgroups: comp.unix.bsd
Subject: Re: Cpio and symbolic links (was Re: stock 0.1 swap not enough.)
Keywords: cpio, bug, symbolic link
Message-ID: <14081@auspex-gw.auspex.com>
Date: 16 Aug 92 10:14:32 GMT
References: <1992Aug9.175542.16722@mks.com> <Bszz1K.28B@twwells.com> <1992Aug15.143740.27391@vuse.vanderbilt.edu>
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Organization: Auspex Systems, Santa Clara
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>Even the SunOS version which was made aware of symlinks by a well-known wizard
I've not tried rewriting UNIX from scratch, so I wouldn't go that far.
:-)
>has problems with symlinks in the presence of some combination of switches (in
>my case "-pdl").
The "net-2" version has the symlink changes I made at Sun in it, which
means it has the same bug. Here's the fix:
*** cpio.c.dist Sun Aug 16 02:59:08 1992
--- cpio.c Sun Aug 16 02:59:16 1992
***************
*** 488,494 ****
i++;
strcpy(fullp, &(Hdr.h_name[i]));
! if( PassLink && !A_directory && Dev == Statb.st_dev ) {
if(link(Hdr.h_name, Fullname) < 0) {
switch(errno) {
case ENOENT:
--- 488,495 ----
i++;
strcpy(fullp, &(Hdr.h_name[i]));
! if( PassLink && !A_directory && !A_symlink
! && Dev == Statb.st_dev ) {
if(link(Hdr.h_name, Fullname) < 0) {
switch(errno) {
case ENOENT:
which tells it not to make hard links to symlinks (in SunOS 4.x, at
least, that results in hard links being made to the target of the
symlink, even if it's a directory, if you have permission to do so; in
SVR4, it results in a hard link being made to the symlink itself, so
that people can still use the crufty old "link()"/"unlink()" hack to
rename files, even if the file is a symlink).
I think I see a place where the "net-2" version can screw up when
writing symlinks out; normally, I'd put a patch out for that, but since
I saw it when comparing the SunOS code I'd fixed here to the "net-2"
code with the same fix applied, I'll not do so, for reasons that should
be obvious to people reading other threads in this group. (1/2 :-))
I *will* say, however, that you should check to make sure that all the
code that writes out stuff does the same sort of thing for symlinks that
it does for other file types; if you do so, you may find the problem....
Then again, there may be a GNU "cpio", which may well be missing that
bug and other bugs.