highlight.awk

    #!/usr
    # AWK hl test

    # BEGIN and END are also matched as patterns
    BEGIN {
    	p = 0;
    }

    /some pattern/ {
    	p++;
    }

    # / inside brackets is not considered end of expression
    # a loose division operator (/) is not mismatched as a pattern.
    $1 =~ /[^abc/]def/ || b == 3 / 5 {

    	gsub ( FILENAME );

    }

    # TODO and FIXME also work in comments in Awk.

    # Also backslash in patterns works.
    /\/usr\/bin\/awk/ { print "This is me"; }

    END {
    	print p;
    }