Compressing, Extracting and Listing with tar
techThe Unix tool tar
is a bit awkward to use because most of the time
it isn’t called with flags like -l
or -v
. With tar
, all flags
are usually smashed together in the first argument.
Luckily, the flags for basic tasks, that is compressing, extracting and viewing, all follow the same pattern, which is easy enough to memorize:
tar {c,x,t}vf{z,j} [archive file] [file]...
First comes tar
, the program itself. Then you can choose from
either c
, x
or t
.
c
is for compressing files into archives.[archive file]
will be the name of the created archive and[file]...
the files you want inside that archive.x
is for extracting files from[archive file]
. In this case,[file]
is omitted.t
is for listing files from[archive file]
(I guess the word list does have the letter t in it). Again,[file]
is omitted.
Then comes v
for verbose output (lets you know what is happening)
and f
for file because per default tar
likes to read and write
from stdin
. Finally there are the optional z
or j
flags. They
enable compression.
z
uses gzip compression, which is fast but not as efficient as some other algorithms. Your archive file should have the.tar.gz
extension.j
uses bzip2, which is slower but more efficient than gzip. A bzip2 archive should have a.tar.bz2
extension.
When extracting files (x
flag), you can actually tell tar
to pick
the correct compression algorithm on its own. Instead of z
or j
,
use a
like this:
tar xvfa [archive file]
Now tar
is way more powerful than this, but for daily use, I
find this to be enough.