Re^3: How To Read Hosts File Into a Hash

[toolic]

Why do I get the "uninitialized error" for $key?

My guess is your input file has a blank line:

while (<FILE>) {
    next if /^\s*#/ ; # skip comments
    next unless /\S/; # skip blank lines
    chomp;
    my ($key, $value) = split;
    $hosts{$key} = $value;
    }

See perlre