What does this command mean: awk -F: '{print $4}'?

Please explain what does following command mean:

awk -F: '{print $4}'

2 Answers

awk -F: '{print $4}'

awk - this is the interpreter for the AWK Programming Language. The AWK language is useful for manipulation of data files, text retrieval and processing
-F <value> - tells awk what field separator to use. In your case, -F: means that the separator is : (colon).
'{print $4}' means print the fourth field (the fields being separated by :).

Let's say that there's a file called test, and it contains the following:

Hello:my:name:is:Alaa

If we execute the command awk -F: '{print $4}' test, the output will be:

is

Because is is the fourth field.

 field1 field3 field5 ----- ---- ---- | | | | | | Hello:my:name:is:Alaa || || -- -- field2 field4

You set the field separator with ...
```
-F
```
so that is ":" in this example.
You print the text that is between the 3th and 4th separator with ...
```
'{print $4}'
```

And this explains it better:

echo "154:266:377:454:533" | awk -F: '{print $4}'
454