Unix password change

[pbinstead]

Hi, How can I change a unix password from a perl program. I can't seem to find any reference to how to do this. Any help would be much appreciated

[Abigail-II]

That's because non-interactive changing of passwords is a dangerous thing. Don't go there unless you're absolutely sure what you're going to do. If you mess up, *NOONE* will be able to log anymore, and you'll need to do some massive recovery. Do you have your backup tapes ready? Do you know which steps to take to recover your system? Have to checked that your backup procedure is actually working? Can you read from your backup tape?

Here's a hint (I ain't going to spoon feed you on things changing the passwords, if you need handhelding, you shouldn't be doing this). /usr/bin/passwd reads directly from the (pseudo)-terminal, not from STDIN.

Abigail

[defyance]

This node may be what your looking for. It talks about a few different ways to do what you need. Personaly, I'd go for the first option, which uses Expect.pm. Before you venture down that road, however, make sure you have a copy of your /etc/passwd made, just to be safe.

-- Can't never could do anything, so give me and inch, I'll make it a mile.

[bronto]

If you want to interface yourself to the passwd program you should use some Expect module. Take a look on CPAN, I can't suggest any Expect module because search.cpan.org is currently unreachable for me.

Otherwise, you can calculate a "crypt string" by means of the crypt function and then substitute the it to the password string in the /etc/passwd file.

Maybe this quick-and-dirty script could help you getting started; I use it to calculate a crypt string, given the password:

#!/usr/bin/perl

print "Password? > " ;
$_ = <STDIN> ;
chomp ;
srand ;
print crypt($_,
            join('',('.', '/', 0..9,'A'..'Z', 'a'..'z')[rand 64, rand 
+64])),
      "\n" ;

Ciao!
--bronto

Update: just a note: the srand was needed to make the script run correctly on some old IBM machines that ran Perl 4.

---

The very nature of Perl to be like natural language--inconsistant and full of dwim and special cases--makes it impossible to know it all without simply memorizing the documentation (which is not complete or totally correct anyway).
--John M. Dlugosz

[Anonymous Monk]

Thanks for the help with this. Works great :-)

[zby]

You can try to use the IPC::Run module to control the passwd program.