use strict;
use warnings;
use Data::Dumper;

my ($str,@match);
$str = "
foo
bar
baz
";

@match = $str =~ /(foo.*bar)/;  # nope!
print Dumper \@match;

@match = $str =~ /(foo.*bar)/m; # nope!
print Dumper \@match;

@match = $str =~ /(foo.*bar)/s; # this one!
print Dumper \@match;

$str = "
foo bar
foo baz
";

@match = $str =~ /^(foo bar)/; # nope!
print Dumper \@match;

@match = $str =~ /^(foo bar)/s; # nope!
print Dumper \@match;

@match = $str =~ /^(foo bar)/m; # this one!
print Dumper \@match;