[Toybox] [PATCH] cpio: Implement -u (copy unconditionally)
enh
enh at google.com
Wed Feb 24 18:21:27 PST 2021
No hurry, I was just checking that something like that hadn't happened 😀
On Wed, Feb 24, 2021, 17:04 Rob Landley <rob at landley.net> wrote:
> Ah, sorry. His email (and the follow up) wound up in gmail's spam filter
> again.
>
> I'll try to take a look tonight.
>
> Rob
>
> On 2/24/21 12:17 PM, enh via Toybox wrote:
> > ping?
> >
> > On Sun, Feb 14, 2021 at 5:13 AM Yi-Yo Chiang via Toybox
> > <toybox at lists.landley.net <mailto:toybox at lists.landley.net>> wrote:
> >
> > If -u is specified, then replace any existing files or directories.
> >
> > If -u is not specified and the path to be inflated already exist,
> then
> > report EEXIST error. This behaves slightly different from GNU cpio,
> as
> > GNU cpio checks the timestamp and replaces when the timestamp of the
> > existing file is older than the one from the archive. This still
> > conforms to SUSv2 as it doesn't define how to behave when -u is not
> > specified.
> >
> > There is an exception, if we are creating an existing directory, then
> > don't report any error or try to rmdir() the directory as we can
> > "create" the directory by chmod() / chown() the existing one.
> >
> > ---
> > tests/cpio.test | 16 ++++++++++++++++
> > toys/posix/cpio.c | 46
> ++++++++++++++++++++++++++++++++++++----------
> > 2 files changed, 52 insertions(+), 10 deletions(-)
> >
> > diff --git a/tests/cpio.test b/tests/cpio.test
> > index 6ab3665a..7e2955a1 100755
> > --- a/tests/cpio.test
> > +++ b/tests/cpio.test
> > @@ -42,4 +42,20 @@ touch a; chmod a-rwx a; ln -s a/cant b
> > toyonly testing "archives unreadable empty files" "cpio -o -H
> newc|cpio
> > -it" "b\na\n" "" "b\na\n"
> > chmod u+rw a; rm -f a b
> >
> > +mkdir a
> > +echo "old" >a/b
> > +echo "a/b" | cpio -o -H newc >a.cpio
> > +rm -rf a
> > +testing "-i doesn't create leading directories" "cpio -i <a.cpio
> > 2>/dev/null; [ -e a ] || echo yes" "yes\n" "" ""
> > +rm -rf a
> > +testing "-id creates leading directories" "cpio -id <a.cpio && cat
> a/b"
> > "old\n" "" ""
> > +rm -rf a a.cpio
> >
> > +mkdir a
> > +echo "old" >a/b
> > +find a | cpio -o -H newc >a.cpio
> > +testing "-i keeps existing files" "echo new >a/b && cpio -i <a.cpio
> > 2>/dev/null; cat a/b" "new\n" "" ""
> > +testing "-id keeps existing files" "echo new >a/b && cpio -id
> <a.cpio
> > 2>/dev/null; cat a/b" "new\n" "" ""
> > +testing "-iu replaces existing files; no error" "echo new >a/b &&
> cpio -iu
> > <a.cpio && cat a/b" "old\n" "" ""
> > +testing "-idu replaces existing files; no error" "echo new >a/b &&
> cpio
> > -idu <a.cpio && cat a/b" "old\n" "" ""
> > +rm -rf a a.cpio
> > diff --git a/toys/posix/cpio.c b/toys/posix/cpio.c
> > index 31c777c9..795f890c 100644
> > --- a/toys/posix/cpio.c
> > +++ b/toys/posix/cpio.c
> > @@ -22,7 +22,7 @@ config CPIO
> > default y
> > help
> > usage: cpio -{o|t|i|p DEST} [-v] [--verbose] [-F FILE]
> > [--no-preserve-owner]
> > - [ignored: -mdu -H newc]
> > + [ignored: -m -H newc]
> >
> > Copy files into and out of a "newc" format cpio archive.
> >
> > @@ -32,6 +32,7 @@ config CPIO
> > -o Create archive (stdin=list of files, stdout=archive)
> > -t Test files (list only, stdin=archive, stdout=list of files)
> > -d Create directories if needed
> > + -u Copy unconditionally
> > -v Verbose
> > --no-preserve-owner (don't set ownership during extract)
> > */
> > @@ -113,7 +114,8 @@ void cpio_main(void)
> > if (FLAG(i) || FLAG(t)) for (;;) {
> > char *name, *tofree, *data;
> > unsigned size, mode, uid, gid, timestamp;
> > - int test = FLAG(t), err = 0;
> > + int test = FLAG(t), err = 0, exist = 0;
> > + struct stat st;
> >
> > // Read header and name.
> > if (!(size =readall(afd, toybuf, 110))) break;
> > @@ -137,25 +139,50 @@ void cpio_main(void)
> > // (This output is unaffected by --quiet.)
> > if (FLAG(t) || FLAG(v)) puts(name);
> >
> > - if (!test && FLAG(d) && strrchr(name, '/') && mkpath(name)) {
> > + if (!test) exist = !lstat(name, &st);
> > +
> > + // Create leading directories if |name| doesn't exist.
> > + if (!test && !exist && FLAG(d) && strrchr(name, '/') &&
> mkpath(name)) {
> > perror_msg("mkpath '%s'", name);
> > test++;
> > }
> >
> > + // Don't report error or try to rmdir(name) if we want to
> mkdir(name)
> > later.
> > + if (!test && exist && !(S_ISDIR(st.st_mode) && S_ISDIR(mode))) {
> > + if (!FLAG(u)) {
> > + errno = EEXIST;
> > + perror_msg_raw(name);
> > + test++;
> > + } else if (S_ISDIR(st.st_mode) ? rmdir(name) : unlink(name)) {
> > + perror_msg("remove '%s'", name);
> > + test++;
> > + } else {
> > + exist = 0;
> > + }
> > + }
> > +
> > // Consume entire record even if it couldn't create file, so
> we're
> > // properly aligned with next file.
> >
> > if (S_ISDIR(mode)) {
> > - if (!test) err = mkdir(name, mode);
> > + if (!test) {
> > + // If |name| already exist as a directory, then just do a
> chmod()
> > to fix
> > + // up the directory permissions.
> > + if (!exist) err = mkdir(name, mode);
> > + else if (S_ISDIR(st.st_mode)) err = chmod(name, mode);
> > + else err = errno = EEXIST;
> > + }
> > } else if (S_ISLNK(mode)) {
> > data = strpad(afd, size, 0);
> > - if (!test) err = symlink(data, name);
> > + if (!test) {
> > + err = symlink(data, name);
> > + // Can't get a filehandle to a symlink, so do special chown
> > + if (!err && !geteuid() && !FLAG(no_preserve_owner))
> > + err = lchown(name, uid, gid);
> > + }
> > free(data);
> > - // Can't get a filehandle to a symlink, so do special chown
> > - if (!err && !geteuid() && !FLAG(no_preserve_owner))
> > - err = lchown(name, uid, gid);
> > } else if (S_ISREG(mode)) {
> > - int fd = test ? 0 : open(name,
> O_CREAT|O_WRONLY|O_TRUNC|O_NOFOLLOW,
> > mode);
> > + int fd = test ? 0 : open(name,
> O_CREAT|O_EXCL|O_WRONLY|O_NOFOLLOW, mode);
> >
> > // If write fails, we still need to read/discard data to
> continue with
> > // archive. Since doing so overwrites errno, report error now
> > @@ -197,7 +224,6 @@ void cpio_main(void)
> > && !FLAG(no_preserve_owner))
> > {
> > int fd = open(name, O_RDONLY|O_NOFOLLOW);
> > - struct stat st;
> >
> > if (fd != -1 && !fstat(fd, &st) && (st.st_mode&S_IFMT) ==
> > (mode&S_IFMT))
> > err = fchown(fd, uid, gid);
> > --
> > 2.30.0.478.g8a0d178c01-goog
> >
> > _______________________________________________
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> > Toybox at lists.landley.net <mailto:Toybox at lists.landley.net>
> > http://lists.landley.net/listinfo.cgi/toybox-landley.net
> >
> >
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> >
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