[Debian] Debian Almquist Shell (dash) xz: Compress and decompress files

Overview

The xz command is used in the Debian Almquist Shell (dash) to compress and decompress files using the LZMA algorithm. It is particularly effective for reducing file sizes, making it a popular choice for distributing software packages and large datasets.

Usage

The basic syntax of the xz command is as follows:

xz [options] [arguments]

Common Options

• -d, --decompress: Decompress the specified files.
• -k, --keep: Keep the original files after compression or decompression.
• -f, --force: Force compression or decompression, even if the output file exists.
• -z, --compress: Compress the specified files (default action).
• -9: Use the maximum compression level (1-9, where 9 is the highest).
• -c: Write the output to standard output instead of a file.

Common Examples

Here are some practical examples of using the xz command:

Compressing a file

To compress a file named example.txt, you can use:

xz example.txt

This will create a file named example.txt.xz and remove the original example.txt.

Decompressing a file

To decompress a file named example.txt.xz, you can run:

xz -d example.txt.xz

This will restore the original example.txt file.

Keeping the original file

If you want to compress a file but keep the original, use the -k option:

xz -k example.txt

This will create example.txt.xz while keeping example.txt intact.

Maximum compression

To compress a file with the highest compression level, use:

xz -9 example.txt

This will create a highly compressed version of example.txt.

Output to standard output

To view the compressed data in the terminal without saving it to a file, use:

xz -c example.txt

This will display the compressed output directly in the terminal.

Tips

• When compressing large files, consider using the -9 option for maximum compression, but be aware that it may take longer.
• If you frequently work with compressed files, consider using the -k option to avoid losing the original files during compression.
• For batch processing, you can use wildcards. For example, xz *.txt will compress all .txt files in the current directory.