use warnings;
use strict;

my $strs = <<STRS;
set zone "VLAN" vrouter "trust-vr"
set zone for "non-matched" stuff
set zone id 100 "Internet_Only"
quoted "stuff" without set zone
STRS

open my $fIn, '<', \$strs;

while (defined(my $line = <$fIn>)) {
    next if $line !~ /^set\szone\s (?:id\s\d+\s)? "([^"]*)"/x;
    my $zone = $1;
    
    chomp $line;
    print "Config line=> $.;    Value=> $line;    zone=> $zone\n";
}

##</code><code>##

Config line=> 1;    Value=> set zone "VLAN" vrouter "trust-vr";    zone=> VLAN
Config line=> 3;    Value=> set zone id 100 "Internet_Only";    zone=> Internet_Only