while ( <DATA> ) {
    my ( $core) = /^foo (.*) bar$/;
    my @nums = $core =~ /m (\d+)/g;
    print "$core -> (@nums)\n";
}

__DATA__
foo m 1 m 2 m 3 m 4 bar
foo m 2 m 4 m 7 bar
foo m 1 bar