On 2/12/21 7:49 PM, enh via Toybox wrote: > attached is "just enough" tar --transform for the kernel use case. adding the
Speaking of, the tar manual has --one-top-level[=dir] which seems to be their version of --restrict, except they do a heuristic on the filename. (How does that work when you zcat a file into it?) > missing FLAGS syntax checking is easy, and sed's unescape_delimited_string() > is > easily moved into lib for reuse for fixing the PATTERN part of > s/PATTERN/REPLACEMENT/FLAGS, but the REPLACEMENT part seems hairy enough that > i > thought i'd stop and ask before ploughing on in this direction... First printf is debug, second should be gated on -v ? + fprintf(stderr, "flags=%s\n", tc->flags); + fprintf(stderr, "%s -> %s\n", name, tname); Style: I'm using the glibc x ? : y syntax these days. + strncpy(hdr.name, tname ? tname : hname, sizeof(hdr.name)); Also, if transform() returns name when it makes no changes you can use the result without testing and then test the free: if (lnkname != lnk) free(lnkname); Sigh, what were the magic barely-documented flags again? Not in the man page... not in the --transform option of the html manual... ah, here they are: https://www.gnu.org/software/tar/manual/tar.html#SEC115 Right after the BROKEN LINK to the sed manual. (The <strike>aristocrats</strike> FSF!) So, rRsShH and the default if nothing is specified is rsh but presumably if you specify "s" it disables "rh" and if you have R but add r after it either that switches the R back off or throws an error? And they have a "flags=" expression syntax which is just _gratuitous_... For H, do they mean all entries _after_ the first, or does that include anything with a link num > 1? (And... why do they have that at all?) + if ((S_ISREG(st->st_mode) && !strchr(tc->flags, 'R')) || + (!link_target || (S_ISLNK(st->st_mode) && !strchr(tc->flags, 'S')))) { + // TODO: do multiple matches if the sed 's' g flag was supplied + // TODO: handle & + if (!regexec(&tc->re, name, 1, m, 0)) { How does that NOT always trigger when !link_target? Even when tc->flags does have an R you'll still trigger when !link_target? I'm sorry, what? 3) Convert each file name to lower case: $ tar --transform 's/.*/\L&/' -x -f arch.tar Really? Does that... $ echo potato | sed 's/./\L/g' $ echo potato | sed 's/.*/\L&/' potato No, it doesn't look like it does. They just made it up HERE. And -v is --show-transformed-names for this? Plus: --anchored --ignore-case --no-anchored --no-ignore-case --no-wildcards --no-wildcards-match-slash --wildcards --wildcards-match-slash Sigh. Ok, the if (TT.transform) hunk doesn't support the crazy flags= syntax (I think I'm ok with that). You have the TODO about separator escaping: $ echo abc/def | sed 's/abc\/def/ghi/' ghi I try not to modify environment data when I can help it because it corrupts ps/top output... sed also has [0-9] as flags to only substitute Nth match. Why weren't we just feeding it through to actual sed again? Because 'p' gets it out of sync and the 'w' command is just a security hole waiting to happen. Sigh... My brain hurts. Rob _______________________________________________ Toybox mailing list [email protected] http://lists.landley.net/listinfo.cgi/toybox-landley.net
