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- In this video

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we are going to talk about
compression utilities.

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There's a couple of compression utilities

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that are commonly used
in a Linux environment.

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To start with, there is gzip.

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If you want to use gzip in
tar, you use the Z option.

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This is the most common
compression utility

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because it's giving a nice
balance between compression ratio

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and time that it takes
to create the archive.

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There is bzip2 or -J,
if you use it in tar,

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that's an alternative utility

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which is offering better
compression, but it takes longer.

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And there is xzip,

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or -J uppercase J in tar
is a utility relatively

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new that offers the best
possible compression

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but is significantly slower.

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And also for those of you who know it

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from other environments,
there is zip utility

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and the zip utility has a
windows compatible syntax.

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The zip utility mainly is
something from history.

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You don't really need it nowadays anymore.

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And that is because windows nowadays also

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reads Linux native
compression formats like gzip.

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If you have a gzip file

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you can easily read
that on windows as well.

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Now, the main difference

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between these compression
utilities is the ratio

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and time it takes to compress

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and you can use time to
measure the time that it takes.

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And well, let me show you how to use it.

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So to start with, I
want to get back to this

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this first tar command that we have used.

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I'm going to modify it a little bit.

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First thing that I'm going to modify

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I am going to compress.

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So I want to that to
be easily seen from the

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the extensions, you can go
to waste for the extension.

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I'm using .tar.z, which
is totally acceptable.

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You could also use .dgz as the extension

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which would also work.

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The next thing that we
need to change is the

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compression option and this
compression option that is the Z

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that I'm going to add.

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And then the final thing that I wanna do

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I want to put the time
command in front of it,

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because there are two things that really

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matter regarding compression

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and that is the compression ratio

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but also the time that it takes.

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So let's record the time so

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that we can actually see
how much time it is taking.

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There we go.

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As you can see, there was
a reasonable eight seconds.

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Okay. That was take one.

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Let's do take two.

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And then take two.

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We are creating bz a bz2 compressed file.

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The extension here really doesn't matter

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because it's just to inform your users.

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So use any extension that you want.

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I am going to use J, J
entire is the option for bz

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to compression and for the rest of it

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we don't need to change anything.

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I want to create an archive
of exactly the same.

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And again, we are going
to record the time.

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We have just seen eight seconds in total.

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So I'm wondering how much
time is this going to take?

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And as you can see more than
double, 22 seconds in total.

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All right, of course you wanna know

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about Contra compression ratio as well.

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We are going to find
out in just a little bit

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but first I want to do my
third run, the xz utility.

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So again, I'm changing the extension

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and we are using uppercase J to make sure

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that we are using the xz utility.

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And there we go running time again

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and let's figure out how long it takes.

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As you can see, the time
it takes to compress,

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this file really takes a lot longer.

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And that is because

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of the compression algorithm that is used.

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But the thing that matters of course

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is what is the compression ratio.

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And we are going to find
out in just a second.

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So what do we see?

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Oh, wow.

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One minute and 10 seconds.

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That is again, more than three times

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the amount of time as the bz2 utility.

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Another thing that we
really wanna know is what

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about compression ratio?

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So ls -l on /tmp files

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.star is showing us

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that the original archive
was 339 megabytes.

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Then we have the gzip
archive, which is, well

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shall we say a hundred?

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The bz2 one is about 90.

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And the xz compressed
archive is only 78 megabytes.

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So for 20% more effective
compression, you need to wait.

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Well, about 10 times as much

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the difference between gzip and xz.

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It's up to you,

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what best fits your needs.

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These are the different utilities.

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Now you can use these utilities

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on the command line as well

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to compress as well as to extract.

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So if I would use gzip, for example

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on /tmp/files.tar

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then we can see that, oh,
automatically it wants to

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to create a file with the extension.

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And it's kindly asking if I
want to overwrite and well

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I don't want to overwrite
you get the idea.

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Gzip will compress and gunzip
will do the decompression.

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And likewise, you can use bzip2 and xz

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from the command line as well.

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But most of the times
you will find yourself

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using the compression utilities

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as an argument to the tar command.