From Linuxintro

To unpack files under Linux, you need to know what file format your file is. Frequently used are the .zip, .tar and .tar.gz formats.

If you want to be sure about the file format, open a console and use the file command like this:

# file Blue-1.7.tar
Blue-1.7.tar: POSIX tar archive (GNU)

Here are file formats and how to unpack them:

extension type how to extract
.7z 7zip install 7z, e.g. for SUSE Linux: yast -i p7zip; run it: 7z x file.7z
.bz2 bunzip2 bunzip2 file.bz2
.rar rar unrar x file.rar
.sda ? unzip file.sda
.tar tar archive tar xvf file.tar
.tar.gz gzipped tar archive tar xvzf file.tar
.tgz gzipped tar archive tar xvzf file.tgz
.zip zip archive unzip file.zip
.zipx new WinZip archive See unpack .zipx files

See also