open FILE, "<", "$hostfile" || die "Cannot open $hostfile $!";

##</code><code>##

open( FILE, "<", $hostfile ) || die "Cannot open $hostfile $!";

##</code><code>##

open FILE, "<", $hostfile or die "Cannot open $hostfile $!";

##</code><code>##

while (<FILE>) {
    chomp;
    my ($key, $value) = split (" ", $_);
    $hosts{$key} = $hosts{$value};
    }

##</code><code>##

while (<FILE>) {
    my ($key, $value) = split;
    $hosts{$key} = $value;
    }

##</code><code>##

while (<FILE>) {
    my ($key, @values) = split;
    push @{$hosts{$key}} = @values;
    }