@ai-ecoverse/wasm-zip

Info-ZIP zip 3.0 and unzip 6.0 for slicc's wasm realm.

pnpm add -g @ai-ecoverse/wasm-zip
zip out.zip file.txt
unzip -l out.zip

• zip -T runs unzip itself, without a shell. A -TT command is a shell command, so it needs one (@ai-ecoverse/wasm-bash).
• Non-ASCII names are UTF-8. zip sets the UTF-8 flag on them, and unzip shows them and reads Info-ZIP's Unicode path field.
• The realm's file names are UTF-8. An entry whose name isn't (an old Latin-1 or CP437 archive without a Unicode path) is not extracted under a changed name: unzip says cannot create <name> / Illegal byte sequence and exits 50. unzip -p still streams its bytes. Such entries are refused rather than renamed because a substituted name can collide with another entry or an existing file and silently overwrite it.
• unzip -% (opt-in) extracts those entries under an escaped name instead. Each byte of the name outside a valid UTF-8 sequence becomes %XX (two upper-case hex digits), and a % in that name becomes %25; a name that is valid UTF-8 is left exactly as it is. So caf\xe9.txt is written as caf%E9.txt and 100%\xe9.txt as 100%25%E9.txt, and unzip prints escaped: <path> for each one. To get the stored name back, replace every %XX in a reported path with the byte XX, e.g. in Python urllib.parse.unquote_to_bytes(name). An escaped name never replaces anything: if its path exists already (on disk, or from an earlier entry), the entry is refused by name, and a later entry whose path an escaped entry took is refused too. unzip then exits 2, also under -o and -n. Symlink targets are not escaped, so a link whose target isn't UTF-8 is still refused.
• A Unix entry with the PKWARE verification bit (internal attribute bit 2) carries a checksum where its mode would be, so it is extracted as a regular file with 0666 (0444 if marked read-only) less your umask, not with the mode 000 that Debian's handling of the bit leaves.
• zip - … > file and zip - … | … write valid archives, and zip -s 0 merges split archives (zip -s 1m) back with every byte.
• zipinfo is unzip's zipinfo mode, the same as unzip -Z.
• unzip carries Debian's unzip 6.0 security patches.