Dear Monks,

I’ve run into a strange little issue. Communicating with another piece of software (actually, Linphone), the command protocol is line based. To make sure there are no newlines in any of the commands, I decided to split and take the first (0th) element and just go with it, discarding the rest — instead of using a regex to do it.

Later on, I figured I’d allow more arguments to the method, joining them with spaces, so I can just pass a list when calling it (and so I don’t have to concatenate variables into the command string all the time).

Long story short, here’s some code:

sub cmd($@) {
    my $self = shift;
    my @cmd = @_;
    
    ## Make sure none of them contain newlines
    for (0 .. $#cmd) {
        $cmd[$_] = [split "\n", $cmd[$_]]->[0];
    }
    
    ## Join words with spaces and send them to linphonec
    print {$self->{Writer}} join(' ', @cmd) . "\n";
}

[download]

Calling it with things like $linphone->cmd("command"), $linphone->cmd("legacy command string I forgot to update\n") or $linphone->cmd("command", $argument1, $argument2) appears to work fine, as split shall return whatever is before the newline and all arguments are happy.

Calling it with $linphone->cmd('') however returns undef, which I feel is a very nasty thing for split to do.

Not sure if I actually have questions, this is probably a known caveat of split, but of course if there’s a way to coerce it to do the right thing, I’m all ears. Until then, I'll just // '' things or something like that.

In reply to Odd workings of split by Ralesk

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