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So let's talk
about tail and head.

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Now what is till till on the text
file showing you the last couple of lines?

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By default it's
the last 10 lines.

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If you want to see more, use till minus number.
So till minus three is only showing the last three lines.

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You can also do the opposite
and that would be using head.

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Head is showing the first couple
of lines and here is the result.

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Now you can also combine them if you
want to see the third line, for instance head

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minus 3 etc wd pipe tail minus 1
and that allows you to see only line 3.

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This is by the way, one of these
examples of what we call the UNIX philosophy.

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And the UNIX philosophy is
about many highly specialized commands that

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can be combined using pipes
to do really powerful things.

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Now one more thing that I need to show
you and that is still F on var log messages.

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The F
is for follow.

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And the result is that
whenever something is happening, well, you

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can see it happening right
now it is updated automatically.

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That is very convenient if you are troubleshooting something and
you are analyzing and trying to understand what is going

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on and you see the relevant message happening immediately. We
ignore these messages here because for what we are doing

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right now, they really don't matter. So let me use
Control C to get out of til minus F. This

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is one example where Q doesn't work to get
out, but Control C is the option that you need.