• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 672
  • Last Modified:

Set user's password in Perl script?


I writing a Perl script which will amongst other things create a load of users on a Linux server. I want to be able to have the script set the password for the new users it creates, and email those to the users (I will have an array with the email addresses in).

At the moment I'm struggling to find a way to set passwords in a Perl script - I can see why its difficult but if I can't do this, my plan is significantly less useful than I had hoped!

Any info welcomed. Thanks in advance.

  • 4
  • 3
  • 2
  • +2
1 Solution
see an example here http://www.experts-exchange.com/OS/Linux/Q_22641743.html
system "sudo /usr/local/bin/chpasswd.sh $user $passwd";
or maybe call a shell script to set it passing in args
you can use usermod to change the password.

georgemasonAuthor Commented:
@rockiroads - I've seen that before - but I'm writing the script to run on a Linux box, not as a web app - how would I apply that in my case?

@vikas - tried the following: system("usermod -p $password $reseller");  (where the two variables contain valid strings) and it doesn't error, but doesn't set the pw either
Protect Your Employees from Wi-Fi Threats

As Wi-Fi growth and popularity continues to climb, not everyone understands the risks that come with connecting to public Wi-Fi or even offering Wi-Fi to employees, visitors and guests. Download the resource kit to make sure your safe wherever business takes you!

I wonder perhaps you have forgotten to convert the plain text password to hash before passing it to usermod? You can use Crypt::PasswdMD5 available from CPAN for this purpose. The attached code snippet works for me, when executed as root.

The following script works for me (Ubuntu):
use Crypt::PasswdMD5 qw(unix_md5_crypt);
my @salt = ( '.', '/', 0 .. 9, 'A' .. 'Z', 'a' .. 'z' );
sub gensalt {
 my $count = shift;
 my $salt;
 for (1..$count) {
  $salt .= (@salt)[rand @salt];
 return $salt;
$reseller = "abb2";
$password = "xyz2";
my $password_hash = unix_md5_crypt($password, gensalt(8));
system("usermod -p '$password_hash' $reseller");

Open in new window

I forgot to mention that the above code is based on the example provided by http://sial.org/howto/perl/password-crypt/ web page.
georgemasonAuthor Commented:
Sounds very promising - I had forgotten (i.e. didn't know I needed to) hash the pw.

I get this error - do I need to install a perl module?

"Can't locate Crypt/PasswdMD5.pm in @INC "
Yes, the module is available from CPAN archive. Try

sudo perl -MCPAN -e 'install Crypt/PasswordMD5'

For this to work your computer has to have internet access, to download modules from CPAN server. If it is the first time you use CPAN, you may get a lot of questions, in general it is safe to accept default options (just press Enter). See also http://perl.about.com/od/packagesmodules/qt/perlcpan.htm for more details.

PS. Some Linux distribution offer better way to do the same, Ubuntu and Gentoo at least, maybe other distributions too.
that sample web code is to take in user input of a userid but the password changing code should still be applicable right?

What command are you using right now to create the user?

On your linux o/s do you have the command useradd? If so then that is one way to create users and in there specify the password also.

useradd [-c comment] [-d home_dir]

    [-e expire_date] [-f inactive_time]
    [-g initial_group] [-G group[,...]]
    [-m [-k skeleton_dir] | -M] [-n] [-o] [-p passwd] [-r]
    [-s shell] [-u uid] login

More info on this can be found here http://linux.about.com/od/commands/l/blcmdl8_useradd.htm

Sorry, I have made a typo in my previous comment. The correct command is

sudo perl -MCPAN -e 'install Crypt::PasswdMD5'
If you run your script as root, you can just call passwd directly.  To run your script as root, either use sudo, or actually run it as root.

To run passwd:
    system("echo $new_password | passwd --stdin $user");

To run your script using sudo:
    1) save your script, for example to myscript.pl
    2) Run like:    sudo myscript.pl
        You may be asked for your password

Or, to run as root:
    1) su
        You will be asked for root's password
    2) myscript.pl
georgemasonAuthor Commented:
Thanks to you all for your suggestions. In the end the one which (a) worked and (b) was simplest was from Adam314 - so points go to him.
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

Featured Post

Improved Protection from Phishing Attacks

WatchGuard DNSWatch reduces malware infections by detecting and blocking malicious DNS requests, improving your ability to protect employees from phishing attacks. Learn more about our newest service included in Total Security Suite today!

  • 4
  • 3
  • 2
  • +2
Tackle projects and never again get stuck behind a technical roadblock.
Join Now