#!/usr/bin/perl

use forks;

my @procs;

for my $procname (qw(foo bar baz)) {
    push @procs,
        threads->new(
            sub {
                $0 = $procname;
                sleep 1;
            }
        );
}

system "ps fT -o pid,cmd";

$_->join() for @procs;

__END__
$ ./837477.pl
  PID CMD
10408 bash -rcfile .bashrc
 5278  \_ /usr/bin/perl ./837477.pl
 5279      \_ /usr/bin/perl ./837477.pl
 5280      \_ foo
 5281      \_ bar
 5282      \_ baz
 5283      \_ ps fT -o pid,cmd