What does the gzip command do in Linux?

The gzip command compresses files using Lempel-Ziv coding (LZ77). It is commonly used to reduce file sizes, especially for text files, and is often combined with tar for archiving directories.

How do I compress a file with gzip?

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

How do I decompress a .gz file?

Use 'gzip -d filename.gz' or 'gunzip filename.gz' to decompress a .gz file.

gzip Command

The gzip command is a popular utility in Linux for compressing and decompressing files. It uses the Lempel-Ziv coding (LZ77) algorithm, which is efficient for reducing the size of various file types, especially text files.

Syntax

gzip [OPTION]... [FILE]...

Description

When you use gzip on a file, it replaces the original file with a compressed version, typically with a .gz extension. To restore the original file, you use the gunzip command or gzip -d. gzip is often used in conjunction with tar to create compressed archives of entire directories.

Common uses include:

Compressing single files to save disk space
Decompressing .gz files
Creating compressed archives (often with tar)
Piping output from other commands for compression

Common Options

Option	Description
`-d, --decompress`	Decompress. Equivalent to `gunzip`.
`-f, --force`	Force compression or decompression even if the file has multiple links or the corresponding file already exists.
`-k, --keep`	Keep (don't delete) input files during compression or decompression.
`-r, --recursive`	Recursively compress or decompress files in directories.
`-v, --verbose`	Display name and percentage reduction for each file compressed or decompressed.
`-c, --stdout`	Write output on standard output; keep original files unchanged.
`-숫자`	Compression level (1-9, 1 is fastest, 9 is best compression). Default is 6.

Examples

Compress a file

                        gzip myfile.txt
                        
                        # Result: myfile.txt.gz (original file is deleted)

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

Decompress a file

                        gzip -d myfile.txt.gz
                        
                        # Result: myfile.txt (original .gz file is deleted)

Decompresses myfile.txt.gz and restores myfile.txt.

Compress and keep original file

                        gzip -k anotherfile.log
                        
                        # Result: anotherfile.log and anotherfile.log.gz both exist

Compresses anotherfile.log but keeps the original file.

Compress with best compression ratio

gzip -9 largefile.data

Compresses largefile.data using the highest compression level.

Compress a directory (using tar and pipe)

tar -czvf archive.tar.gz mydirectory/

Creates a gzipped tar archive of mydirectory/. (Note: -z option in tar handles gzip).