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To work with structured text cells
efficiently, it can be useful to filter

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out specific columns, because many text
cells on Linux are organized in columns.

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The ETCPass WD file is a nice example.
It contains users that are defined on your

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system, and cut is an easy to use
command that filters out columns from text files.

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To do its work properly, you need to specify the
field delimiter for cut. That would be the option D.

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To understand, compare the result
of the command cut f3etcpass wd,

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which is trying to filter
the third field without specifying the

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field delimiter and Compare that
to cut D F3 etcpasswd.

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You'll see that it
is much more efficient.

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A utility that you will find a
lot in combination with cut is Sort.

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Because it sorts the output of the
cut command by default in alphabetical order.

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You can use the n
option to sort in numeric order.

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Compare the following, for
instance cut d, f3 etc

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wdsort and sort n.
Let me show you.

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So to start
with good minus

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f3 etcwd
is doing what?

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Well, nothing that makes sense because cud
doesn't know how to recognize the fields.

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What we see here, if you look at the last
line for user lorry, for instance, first field has the

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username, the third field has the user id, and
there is more information that we will talk about later.

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Now, if I want to tell cut to
do this in an efficient way, let's make

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that cut d colon there. You can
see that it filters out the third column.

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Now we can sort that by sending it
to sort. But this is an alphabetic sort,

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so all ones first, all twos next, all
3s next, and so on. That's not probably

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what you want. So make that sort
n to make it a nice numeric sort.

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And that's how you can use sort
and cut, which are two convenient utilities together.