[Toybox] [PATCH] cpio: Implement -u (copy unconditionally)

Rob Landley rob at landley.net
Wed Feb 24 17:17:42 PST 2021


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
> 
>     _______________________________________________
>     Toybox mailing list
>     Toybox at lists.landley.net <mailto:Toybox at lists.landley.net>
>     http://lists.landley.net/listinfo.cgi/toybox-landley.net
> 
> 
> _______________________________________________
> Toybox mailing list
> Toybox at lists.landley.net
> http://lists.landley.net/listinfo.cgi/toybox-landley.net
> 


More information about the Toybox mailing list