Learning Linux Shell Scripting - Second Edition

Using awk

The following are different ways to use awk:

• Syntax while using only pattern:

    $ awk 'pattern' filename
  

• In this case, all the lines containing pattern will be printed.

• Syntax using only action:

    $ awk '{action}' filename
  

• In this case, action will be applied to all lines.

• Syntax using pattern and action:

    $ awk 'pattern {action}' filename
  

• In this case, action will be applied on all the lines containing pattern.

As seen previously, the awk instruction consists of patterns, actions, or a combination of both.

Actions will be enclosed in curly brackets. Actions can contain many statements separated by a semicolon or a newline.

awk commands can be on the command line or in the awk script file. The input lines could be received ...