arcedit

arcedit changes archives in place, without unpacking and repacking them: rename, delete and add entries, and change their comments (file notes) and protection bits. It is a Shell command, so file managers and scripts can use it too, like they use LhA.

What it can do

• Only the changed parts are written: a delete copies the other entries byte for byte, a rename or comment rewrites only that entry's header, an add packs only the new files. Changing one comment in a 100 MB archive takes a moment, not a full repack.
• Self-extracting LHA archives and all LHA header levels (0, 1, 2) work.
• Drawers: deleting or renaming a drawer changes everything in it; added drawers come with all their contents.
• Added files keep their protection bits, file note and date.
• Safe: the new archive is written to a temporary file next to the old one and replaces it only when everything worked. Before writing, arcedit checks free space, write protection and memory. Ctrl-C stops it and leaves the archive as it was. WORKDIR puts the temporary files in another drawer.
• No libraries needed.

Examples

arcedit Work:a.lha docs/old.txt DELETE
arcedit Work:a.lha DELETE FROM RAM:list
arcedit Work:a.lha RENAME docs/a.txt AS docs/b.txt
arcedit Work:a.zip docs/a.txt COMMENT "a note"
arcedit Work:a.lzx docs/a.txt PROTECT +s-d
arcedit Work:a.lha ADD RAM:new.txt RAM:Drawer TO docs
arcedit Work:a.zip INFO
arcedit Work:a.lha docs DELETE WORKDIR RAM:

Template:

ARCHIVE/A,ENTRIES/M,DELETE/S,RENAME/K,AS/K,COMMENT/K,PROTECT/K,ADD/S,TO/K,FROM=LIST/K,INFO/S,WORKDIR/K,QUIET/S

For programs that use arcedit

arcedit <archive> INFO prints one line, the archive type and the operations this archive allows, for example ZIP: DELETE RENAME COMMENT PROTECT ADD. It reads only the first bytes of the archive, so it is instant for any archive size, and lists nothing when the archive can't be replaced (write protected volume, delete protected archive).

When an operation fails, the last line of the output is Error: <message>, the return code is 10 (20 when out of memory) and the archive is unchanged. Return code 5 with Warning: lines means some entries weren't in the archive; the others were done.

Installation

Double-click Install, or copy C/arcedit to C:. The documentation is in arcedit.txt.

History

• 1.1 (2026-11-15): WORKDIR keeps the temporary files in another drawer. PROTECT on an LHA entry made on Unix removes its Unix permission header, so xadmaster and other readers show the new bits.
• 1.0 (2026-11-15): first release.

arcedit is public domain, all its code is written for it (the Deflate and -lh5- packers too).