Shell Programming and Scripting

stty -echo 
read -r pswd
stty echo

       ReadMode MODE [, Filehandle]
               Takes an integer argument, which can currently be one of the
               following values:

                   0    Restore original settings.
                   1    Change to cooked mode.
                   2    Change to cooked mode with echo off.
                         (Good for passwords)
                   3    Change to cbreak mode.
                   4    Change to raw mode.
                   5    Change to ultra-raw mode.
                         (LF to CR/LF translation turned off)

-- excerpt from perldoc Term::ReadKey, q.v.

#!/usr/bin/perl

use Term::ReadKey;

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

print "\nEnter password: ";

# Loop until enter key is pressed 
ReadMode(4);
while(ord($key = ReadKey(0)) != 10)
{
    if(ord($key) == 127 || ord($key) == 8) {
        chop($password);
        print "\b \b";
    } elsif(ord($key) < 32) {
        # control characters
    } else {
        $password = $password.$key;
        print "*";
    }
}                                                                                                        
ReadMode(0);

print "\n\nYou entered: $password\n";