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WINJAB
Guide

Guide

Guide

The common jobs, in order, with what each choice costs.

1

Make an archive

  1. Open Compress from the rail on the left, or press New Archive in the toolbar.

  2. Add files or a folder. The list accepts both, and a folder keeps its structure.

  3. Check where it will be saved. WINJAB fills this in beside the first thing you added; change it with Choose…

  4. Pick a format: .jab for the fastest write and per-block checksums, .zip or .7z when someone else has to open it.

  5. Pick a mode: Lightning is fastest, Compact is smallest, Balanced sits between them.

  6. Press Start compressing. The overlay shows progress; Run in background returns you to the window while it finishes.

Verify after writing is on by default: the archive is read back and checked once it is written. It costs a re-read and it is the only way to know the file on disk is the file that was meant.

2

Extract one

  1. Open Extract, choose the archive, choose the folder to unpack into.

  2. Decide what happens to a file that already exists: Stop is the default because it is the only choice that cannot lose data you have.

  3. Press Start extracting.

Paths that would escape the folder you chose are refused rather than sanitised silently. Timestamps and attributes are restored unless you turn that off in Settings.

3

Protect an archive with a password

  1. Choose the WINJAB (.jab) format — the other two cannot carry a password here.

  2. Open the Password panel and tick Protect this archive with a password.

  3. Type the password twice. There is no recovery: write it down somewhere you trust.

  4. Compress as usual. Contents, file names and per-block hashes are all encrypted.

Opening a protected archive asks for the password once and answers a wrong one after a single derivation, so a typo costs under a second rather than a full decode.

4

Split a big archive, and put it back

  1. Open Tools and choose the archive.

  2. In Split and merge, pick 10, 25, 100 or 700 MB — or type a size. The panel says how many parts that makes for this archive.

  3. Press Split archive. The parts are written beside the original as .001, .002, …

  4. To rebuild, press Merge parts… and choose the .001 file. Every part is checked before anything is written.

A part on its own is not an archive and cannot be opened: WINJAB merges before reading. A missing part stops the merge with the number of the part that is missing, and leaves no half-written file.

5

Survive damage

  1. Add a recovery record when you create the archive: Recovery record, then how much to reserve, 1% to 30%.

  2. If the file is later damaged, open Tools and press Scan for damage. It reports which shards are wrong and writes nothing.

  3. Press Repair archive to rebuild exactly those parts.

A record has to exist before the damage: it cannot be added to an archive that is already broken, and only .jab can carry one. It undoes accidents — a bad sector, an interrupted transfer, bit rot — not tampering, because whoever can edit the data can recompute the record.

6

Check an archive you were sent

  1. Open Tools and choose the archive.

  2. Check thoroughly reads the structure and then decodes every block, comparing CRC-32C and SHA-256.

  3. Decode only skips the structural pass when you just want to know whether it decodes.

Neither check proves an archive was not tampered with. Only a password-protected archive can answer that, and then only because the attacker would need the password.

7

Add it to the right-click menu

  1. Open Settings and find Windows Explorer integration.

  2. Choose which entries you want: compress, extract here, extract to a folder, test.

  3. Install adds them; Remove takes them away again.

Nothing is added to Explorer unless you ask for it, and removing it leaves nothing behind.

On the command line

The same engine as the window. Run jab with no arguments for the full list.

jab c <sources> -o out.jab

Create an archive. --mode lightning|balanced|compact, --chunk, --recovery 1-30, --no-verify.

jab x archive.jab -o folder

Extract. --overwrite fail|skip|overwrite, --no-times, --no-attrs.

jab l archive.jab

List what is inside.

jab t archive.jab

Decode everything and discard it: the fastest honest check.

jab v archive.jab

Verify structure and data.

--threads auto|N --memory 512M

How many workers, and the ceiling on buffers held between them.

--integrity full|crc

SHA-256 plus CRC-32C per block, or CRC-32C alone.

--password-stdin

Read the password from stdin. Passing it as an argument is refused on purpose: a running process's command line is readable by other processes under the same account.

Keyboard

Tab / Shift+Tab
Walk the controls. The view scrolls to whatever the focus reaches.
Enter / Space
Press the focused control.
Page Up / Page Down
Scroll a screenful.
Esc
Close the task overlay, cancel a preview that is still loading, or drop the focus ring.
Ctrl+P
Show or hide the preview pane in the archive viewer.