#!/usr/bin/env perl

use strict; use warnings;
use Const::Fast;
use Imager;
use Imager::Screenshot qw( screenshot );
use Win32::GuiTest qw( FindWindowLike SetForegroundWindow );

const my $TYPE => 'bmp';
#my $TYPE = 'bmp';
my @windows = FindWindowLike(0,
    '(?:Chrome)|(?:Firefox)|(?:Opera)'
);

for my $hwnd (@windows) {
    warn "$hwnd\n";
    SetForegroundWindow $hwnd;
    sleep 1;
    my $img = screenshot(hwnd => $hwnd, decor => 1);
    die Imager->errstr unless $img;

    $img->write(file => "$hwnd.$TYPE", type => $TYPE)
        or die $img->errstr;
}
[download]