uberdisco has asked for the wisdom of the Perl Monks concerning the following question:

So my issue is Term::ReadKey is broken for me. When I use something like the attached code I see nothing until I hit enter. I have tried all the different options the module allows to no avail. The sample code is just that, a sample of code that doesn't work, I have simplified the code down to its bare essentials and tried that to no avail. Any ideas? Perhaps its my terminal? 
#!/usr/bin/perl

use strict;
use warnings;
use Term::ReadKey;

my $key = 0;
my $password = "";

print "\nPlease input your password: ";

# Start reading the keys
ReadMode(4); #Disable the control keys
while(ord($key = ReadKey(0)) != 10)
# This will continue until the Enter key is pressed (decimal value of 
+10)
{
    # For all value of ord($key) see http://www.asciitable.com/
    if(ord($key) == 127 || ord($key) == 8) {
        chop($password);
        #2 move the cursor back by one, print a blank character, move 
+the cursor back by one
        print "\b \b";
    } elsif(ord($key) < 32) {
        # Do nothing with these control characters
    } else {
        $password = $password.$key;
        print "*(".ord($key).")";
    }
}
ReadMode(0); #Reset the terminal once we are done
print "\n\nYour super secret password is: $password\n";

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Re: Problems with Term::ReadKey (output problem, not input)
by tye (Sage) on Sep 17, 2011 at 19:11 UTC

    Add $|= 1;. (perlvar)

    Update: You should also treat chr(13) the same as chr(10) as the raw mode you are putting things into means that the default translation to a "\n" upon input of a "\r" is disabled (at least in some environments). I had to type Ctrl-J to get it to end.

    - tye        

[reply]
      Adding 
      $|= 1;

      [download]
      solved the problem. Thank you very much, this was driving me nuts! Cheers, uberdisco
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Re: Problems with Term::ReadKey
by Khen1950fx (Canon) on Sep 18, 2011 at 08:22 UTC
    I had to Ctrl-J also. You need a way to get out if necessary. What if the user had second thoughts about putting his password out there, and wanted to quit? 
    exit 0 if $key eq 'q';

    [download]
    Here's what I tried: 
    #!/usr/bin/perl -slw

use strict;
use Term::ReadKey;

my $key = 0;
my $password = "";

print "\nPlease input your password: ";

ReadMode(4);
while(ord($key = ReadKey(0)) != 10) {
    exit 0 if $key eq 'q';
    if(ord($key) == 127 or ord($key) == 8) {
        chop($password);
        print "\b \b";
    } 
    elsif(ord($key) < 32) {
        ();
    } 
    else {
        $password = $password . $key;
        print ord($key);
    }
}
ReadMode(0);
print "\n\nYour super secret password is: $password";

    [download]
    Update: If 'q' is a problem for you, substitute a fake password like 'quit', 'exit', 'bye', etc. for 'q';
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Re: Problems with Term::ReadKey
by pvaldes (Chaplain) on Sep 18, 2011 at 13:38 UTC
    See nothing until I hit enter. Perhaps its my terminal?

    I think so, it runs smoothly in my system without a warning and I can see the chars before enter, then the program exit correctly. Same behaviour when running the script in a tty

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