---
name: "unzck"
section: "1"
platform: "linux"
package: "zchunk"
version: "1.5.4-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/unzck"
---

# unzck(1)

decompress a file in the zchunk format

## NAME

**unzck** – decompress a file in the zchunk format

## SYNOPSIS

**unzck** \[**-c** \| **--stdout**\] \[**--dict**\] \[**-v** \| **--verbose**\] *file*

**unzck** **-**? \| **--help**

**unzck** **--usage**

**unzck** **--version**

## DESCRIPTION

The **unzck** utility extracts the original file from a zchunk-compressed one.

*NOTE:* The **unzck** utility will place the new file without the *.zck* extension in the *current* working directory, not in the directory where the original file resides.

The **unzck** utility accepts the following optional arguments:

- **-c**, **--stdout**

  Extract the data to the standard output stream, do not write it to a file.

- **--dict**

  Only extract the zstd compression dictionary.

- **-v**, **--verbose**

  Verbose operation; display some diagnostic output.

- **-**?, **--help**

  Display program usage information and exit.

- **--usage**

  Display brief program usage information and exit.

- **--version**

  Display program version information and exit.

## EXIT STATUS

The **unzck** utility exits 0 on success, and \>0 if an error occurs.

## EXAMPLES

Create (in the current directory) an uncompressed *words* file from a compressed one:

```
unzck /mnt/xfer/words.zck
```

Do not create the *words* file, but send the contents to the standard output stream:

```
unzck -c /mnt/xfer/words.zck
```

## SEE ALSO

[zck(1)](/zck/1.md), [zck\_delta\_size(1)](/zck_delta_size/1.md), [zck\_gen\_zdict(1)](/zck_gen_zdict/1.md), [zck\_read\_header(1)](/zck_read_header/1.md), [zckdl(1)](/zckdl/1.md)

## AUTHOR

The **unzck** utility was written by Jonathan Dieter ⟨jdieter@gmail.com⟩. This manual page stub was written by Peter Pentchev ⟨roam@ringlet.net⟩.