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

I would like to get a username / password combination with Term::ReadLine in a way that echos the username as it is typed but obscures the password.

With 

  my $term = new Term::ReadLine;
  print $term->ReadLine;

[download]
I can tell that my Term::ReadLine is using Term::ReadLine::Perl, which is, ahem, lacking in documentation. I can see from this example that 
  $attribs = $term->Attribs;
  $attribs->{redisplay_function} = $attribs->{shadow_redisplay};
  $password = $term->readline("Password: ");
  $term->remove_history($term->where_history);

[download]
would do the trick if I was using a Term::ReadLine::* that supported the shadow_redisplay attribute. But alas, Term::ReadLine::Perl does not: 
  starky@freak bin $ ./readline-password-test.pl 
  Term::ReadLine uses [Term::ReadLine::Perl]
  Username:  uname
  Password:  passwd
  The username is [uname] and the password is [passwd]
  starky@freak bin $

[download]

Suggestions?

Replies are listed 'Best First'.
Re: Reading a password with Term::ReadLine
by TilRMan (Friar) on May 11, 2004 at 07:12 UTC 
    use Term::ReadKey;

ReadMode('noecho');
ReadMode('raw');
my $pass = '';

while (1) {
  my $c;
  1 until defined($c = ReadKey(-1));
  last if $c eq "\n";
  print "*";
  $pass .= $c;
}

ReadMode('restore');
print "\n[$pass]\n";

    [download]

    Thanks to asarih and BUU.

[reply]
[d/l]
      ++ Great snippet, I actually have a use for this.
      May I suggest inserting the following, just before your 'use Term::ReadKey;' line? 
      $|=1; #Turn on AutoFlush

      [download]

      On my system (Sun solaris 9 perl 5.8.0) I was consistently seeing 1 less asterisk until I hit the enter key. This should provide a little less confusion for folks entering passwords and not seeing asterisks echoed immediately.
      Thanks.


      Very funny Scotty... Now PLEASE beam down my PANTS!
[reply]
[d/l]
Re: Reading a password with Term::ReadLine
by asarih (Hermit) on May 11, 2004 at 03:43 UTC
    Do you have to use Term::ReadLine? If not, see perldoc -q password. 
                 First, you put the terminal into "no echo" mode,
             then just read the password normally.  You may do
             this with an old-style ioctl() function, POSIX
             terminal control (see POSIX or its documentation the
             Camel Book), or a call to the stty program, with
             varying degrees of portability.

             You can also do this for most systems using the
             Term::ReadKey module from CPAN, which is easier to
             use and in theory more portable.

                 use Term::ReadKey;

                 ReadMode('noecho');
                 $password = ReadLine(0);

    Probably easier using Term::ReadKey.

[reply]
      You missunderstand. He wants to read a password and echo non-descriptive characters for every letter you type, for example, asterisks.
[reply]

Back to Seekers of Perl Wisdom