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PHP Learner
Asked: 2013-09-08 22:36:16 +0800 CST

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

  • 772

Please explain what does following command mean:

awk -F: '{print $4}'
command-line

2 Answers

  1. Best Answer
    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 :).

    Example:

    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
    • 70

    • 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
    • 9