Re-prompting for user input

[jeffkatyspanky]

I am prompting for the user to enter an IP address and I can't figure out a cleaner way to re-prompt if the user enters something other than a valid IP address. I'd like to just clear the "bad" entry and redisplay the prompt on the same line. Any ideas?

Thanks in advance for your help.

Here's my code so far:

sub get_wap2gwip {
    print "WAP2 Gateway IP address? ";
    $wap2gwip = <>;
    $wap2gwip=~/(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})/;
    if($1<256 && $2<256 && $3<256 && $4<256 && ($1+$2+$3+$4)>0) {
        print "Valid IP address. Next . . .\n";
    } else {
        print "That's not a valid IP address.\n";
        &get_wap2gwip;
    }
}
 

[miller]

First of all, your regex for testing is incomplete as it does not contain anchors. This will lead to false matches such as 1111101.12.43.13243

If you really want to do this then you'll need to use something other than <STDIN> to accept input. This is because <STDIN> waits for a return character before returning and mirrors that output to the screen. To avoid that you're going to have to use one of the terminal modules that gives you more control. Here's one that would work.

cpan Term::InKey

Also, for module to handle your ip validation, use the is_ipv4 function of the following module:

cpan Data::Validate::IP

- Miller