What does the bzip2 command do in Linux?

The bzip2 command compresses files using the Burrows-Wheeler block-sorting text compression algorithm, which typically achieves higher compression ratios than gzip.

How do I compress a file with bzip2?

Use 'bzip2 filename' to compress a file. This will replace the original file with a .bz2 compressed version.

How do I decompress a .bz2 file?

Use 'bzip2 -d filename.bz2' or 'bunzip2 filename.bz2' to decompress a .bz2 file.

bzip2 Command

The bzip2 command is a data compressor that uses the Burrows-Wheeler block-sorting text compression algorithm, and Huffman coding. It generally achieves a higher compression ratio than the more common gzip.

Syntax

bzip2 [ options ] [ filenames ... ]

Description

bzip2 compresses the specified files. Each file is replaced by its compressed version, with the name original_name.bz2. If no filenames are specified, bzip2 compresses from standard input to standard output.

Common uses include:

Compressing single files
Decompressing .bz2 files
Compressing data from standard input

Common Options

Option	Description
`-d, --decompress`	Force decompression
`-z, --compress`	Force compression
`-k, --keep`	Keep (don't delete) input files during compression or decompression
`-f, --force`	Force overwrite of output files
`-v, --verbose`	Be verbose during operation
`-c, --stdout`	Compress or decompress to standard output
`-s, --small`	Reduce memory usage, at cost of speed

Examples

Compress a file

                        bzip2 myfile.txt
                        
                        # Result: myfile.txt.bz2 (original file is deleted)

Compresses myfile.txt and replaces it with myfile.txt.bz2.

Decompress a file

                        bzip2 -d myfile.txt.bz2
                        
                        # Result: myfile.txt (original .bz2 file is deleted)

Decompresses myfile.txt.bz2 and restores myfile.txt.

Compress and keep original file

                        bzip2 -k anotherfile.log
                        
                        # Result: anotherfile.log and anotherfile.log.bz2 both exist

Compresses anotherfile.log but keeps the original file.

Decompress to standard output

bzip2 -dc compressed.bz2 > decompressed.txt

Decompresses compressed.bz2 and redirects the output to decompressed.txt.

Compress a directory (using tar and pipe)

tar -cf - mydirectory/ | bzip2 -c > mydirectory.tar.bz2

Compresses an entire directory by piping tar output to bzip2.