#!/usr/bin/env perl

use strict;
use warnings;
use feature 'say';

use DDP { deparse => 1 };

my $strings = 'ssddperffgggperlasdf';
my $target = 'perl';
my @strings = split(//, $strings);
my @target = split(//, $target);

my $count = scalar @strings - scalar @target;

for my $i (0..$count){
    if ($strings[$i] eq $target[0]){
        for my $j (1..((scalar @target) - 1)){
            last if $strings[$i + $j] ne $target[$j];
            if ($j == ((scalar @target) - 1)){
                say "match index:$i";
                exit;
            }
        }
    }
}