You can extract or decompress the tar.bz2,  .bz2,  .gz command on Linux/Unix.

How to Extract : .gz :

$  gunzip   filename.gz

How to Extract :  bz2:
 
$  bzip2  -d  filename.bz2

-d --decompress  : Force decompress

or
 
$  bzip2  -dk  filename.bz2

 -k --keep : keep original file.

or
 
$  tar -xvjpf filename.bz2

or
 
$  bunzip2  filename.bz2

How to Extract : tar.bz2 :
 
$  tar jxf filename.tar.bz2


x - extract

v - verbose output (shows lists all files as they are extracted)

j - deal with bzipped file