sub test {
    my @rv = $_[0] =~ /^([0-9]+)$/;
    print "<<@rv>>\n";
    return @rv[ 0 .. $#rv ];
}

##</code><code>##

<<>>
[[]
<<>>
[]
<<123>>
[123]
<<123>>
[123]

##</code><code>##

sub test {
    my @rv = $_[0] =~ /^([0-9]+)$/;
    print "<<@rv>>\n";
    return wantarray? @rv: $rv[-1];
}


##</code><code>##

michael$ perl t.pl
<<>>
Use of uninitialized value in print at t.pl line 5.
[]
<<>>
[]
<<123>>
[123]
<<123>>
[123]