Just to throw my two bits into the ring, the following is a piece of code that I have used for just what you ask, generating username and password entries for htpasswd files - I think I lifted this code originally from the first edition of Learning Perl.

#!/usr/bin/perl -Tw

use strict;

@salt = ('a' .. 'z', 'A' .. 'Z', '0' .. '9', '.', '/');

my ($username, $password) = @ARGV;

my $now = time;
my ($pert1, $pert2) = unpack("C2", $username);
my $salt = $salt[($now / 604800 + $pert1 + $pert2) % 64] . $salt[$now 
+% 64];
$password = crypt($password, $salt);

print STDOUT "$username:$password\n";

exit 0;
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The salt for encryption in this case is based upon the first two characters of the username and the current system time.

 

perl -e 's&&rob@cowsnet.com.au&&&split/[@.]/&&s&.com.&_&&&print'