#!/usr/bin/perl

use warnings;
use strict;

my $input_file = 'dump.vcd';

open (INPUT, '<', $input_file)
    or die $!;

while (<INPUT>) {
    s/\$var\w \d+ ([!,\#,\",\$,\%,&]) (\w) \$end/\$var $1 $2/;
    print;
}

close INPUT;