#!/usr/bin/perl
use Tk;

sub go {
    local $SIG{CHLD} = 'IGNORE';   # don't wait for child
                                   # exit status. avoids
                                   # zombies.
    die "fork failed: $!" unless defined($pid = fork);
    return if $pid;
    exec("xterm");
    warn "exec failed: $!";
    CORE::exit(1);
}

$m = tkinit; 

$m->Button(-text=>"Foo",-command=>sub{print"Foo\n"})->pack;
$m->Button(-text=>"Go",-command=>\&go)->pack;

MainLoop;