Question

The following AWK format:

/REGEX/ {Action}

Will execute Action if the current line matches REGEX.

Is there a way to add an else clause, which will be executed if the current line does not matches the regex, without using if-then-else explicitly, something like:

/REGEX/ {Action-if-matches} {Action-if-does-not-match}

Answer 1

Not so short:

/REGEX/ {Action-if-matches} 
! /REGEX/ {Action-if-does-not-match}

But (g)awk supports the ternary operator too:

{ /REGEX/  ? matching=1 : matching = 0 ; if ( matching ==1 ) { matching_action } else { notmatching_action } }

UPDATE:

According to the great Glenn Jackman you can assign variables on the match like:

m = /REGEX/ { matching-action } !m { NOT-matching-action }