Linux commands: gunzip

The gunzip command decompresses files that were compressed in the gzip format, the ones ending in .gz. It is the counterpart of the gzip command: the two are the same program wearing different names, except in gunzip the -d (decompress) option is always enabled by default.

The command can be invoked in this way:

gunzip filename.gz

This will gunzip and will remove the .gz extension, putting the result in the filename file. If that file exists, it will overwrite that.

Notice the compressed file is gone afterwards. Check with ls:

ls
# filename

If you want to keep the .gz file around too, add the -k option:

gunzip -k filename.gz
# now you have both filename and filename.gz

You can extract to a different filename using output redirection using the -c option:

gunzip -c filename.gz > anotherfilename

-c writes the decompressed data to standard output instead of to a file, and the > redirection saves it wherever you want. The original .gz file stays untouched in this case too.

Before extracting, you can check what you will get with -l, which lists the compressed and uncompressed sizes:

gunzip -l filename.gz

Two failures you will run into sooner or later. First, running gunzip filename on a file without a recognized extension stops with unknown suffix -- ignored: gunzip only processes files it knows it created.

Second, gzip compresses a single file, never a folder. When you see project.tar.gz, that is a tar archive that was gzipped afterwards. Running gunzip project.tar.gz gives you project.tar, and you unpack that with the tar command — or let tar -xzf project.tar.gz do both steps at once.

The gunzip command works on Linux, macOS, WSL, and anywhere you have a UNIX environment