gunzip

View documentation for the original command

$ tldr gzip

gunzip [options] [file ...]

-a, --ascii
    Treat input as ASCII text; translate LF to CRLF on output

-c, --stdout, --to-stdout
    Write output to stdout, keep original files

-d, --decompress, --uncompress
    Explicitly decompress (default behavior)

-f, --force
    Force overwrite of existing files without prompting

-h, --help
    Display help and exit

-k, --keep
    Keep original compressed files after decompression

-l, --list
    List compressed file details (size, ratio, etc.)

-L, --license
    Display gzip license

-N, --name
    Use original filename and timestamp from gzip header

-q, --quiet, --silent
    Suppress all warnings

-r
    Travel directories recursively (with -N or -k)

-R
    Travel all subdirectories recursively

-S suffix, --suffix=suffix
    Use specified suffix instead of .gz

-t, --test
    Test integrity without decompressing

-v, --verbose
    Verbose mode; print filenames and stats

-V, --version
    Display version and exit

gunzip is a command-line utility for decompressing files compressed with the gzip algorithm. It is part of the gzip package, which provides lossless compression using a combination of LZ77 and Huffman coding.

By default, gunzip replaces the input file (named file.gz) with the decompressed version (file). It automatically detects the .gz suffix or user-specified suffixes. If the output file exists, it prompts for confirmation before overwriting, unless forced.

It supports processing multiple files, standard input (if no files given), and recursive operation on directories. Output can be directed to stdout for piping. Common uses include extracting archives in scripts, testing compression integrity, and listing compressed file details without decompressing.

gunzip preserves file permissions and timestamps (with -N). It handles concatenated gzip files by decompressing until the first complete member. Errors like corrupted data trigger warnings, but processing continues unless quiet mode is set.

Implemented in portable C, it's available on Unix-like systems, including Linux, and is a de facto standard for .gz files, widely used in web servers (gzip encoding), software distribution, and log rotation.

Does not decompress non-gzip formats (e.g., .bz2, .xz); assumes .gz suffix by default; may fail silently on corrupted data unless verbose; recursive mode (-r/-R) requires compatible options like -N or -k.

If no files specified, reads from stdin and writes to stdout. Automatically removes .gz extension on decompression.

Supports multiple concatenated gzip streams; decompresses until EOF or incomplete member.

Developed by Jean-loup Gailly and Mark Adler in 1992-1993 as part of the gzip program, a free reimplementation of compress with patent-free LZ77+Huffman. gunzip extracted as standalone in early versions. Widely adopted after Unix compress patent expired (1993); now POSIX-standard utility in most Linux distros and BSD.

gzip(1), zcat(1), zless(1), zdiff(1), zmore(1)