return $inp or "";

##</code><code>##

$ perl -le'
sub prompt {
    my $inp = shift;
    return $inp or "zzz";
    }
print prompt( $_ ) for undef, 0, 1, 2;
'

0
1
2


##</code><code>##

$ perl -le'
sub prompt {
    my $inp = shift;
    return $inp || "zzz";
    }
print prompt( $_ ) for undef, 0, 1, 2;
'
zzz
zzz
1
2


##</code><code>##

while ( chomp(my $inpt = <STDIN>) != 0  ) {

##</code><code>##

while ( my $inpt = <STDIN>  ) {
    chomp $inpt;


##</code><code>##

			system("ifconfig wlan0 up") if ( (my $ifconf = `ifconfig`) !~ /wlan0/ ); 

##</code><code>##

			system 'ifconfig wlan0 up' if `ifconfig` !~ /wlan0/;