Expect help

[jewel464g]

I first asked this question in the perl forum and was told about expect. So I'm hoping someone here can help me better. I have a perl script that runs this command at the command line.

/sbin/passwd $user

where $user contains the user name, when this is run it prompts for the password, my problem is that since it doesn't return control to the program until after a password is typed in, I can't pass it the password. I was told in the perl forum that I could use expect, but I have no idea how to do that. Can anyone help? Please keep in mind that I have never used this before and didn't even know it existed until yesterday. Below is my script.
Thanks,
Jewel


#!/usr/bin/perl -w

use FileHandle;

open (FILE, "smusers.txt&quot || die "opening smusers.txt";

my @file = <FILE>;
for($index=0; $index<@file; $index++){
$str = $file[$index];
my ($user,$password) = $str =~ /^(.*?):.*.*?)$/;
`/usr/sbin/adduser $user -g pop -s /bin/false`;
`/sbin/passwd $user`;
`su - $user`;
`/var/qmail/bin/maildirmake $\HOME/Maildir`;
`exit`;
$SIG{CHLD} = 'IGNORE';
}

close (FILE); #close the old file

http://www.scriptchick.com/

When faced with a decision, always ask, 'Which would be the most fun?'

 

[marsd]

Hi Jewel,

This is easy stuff for expect of course ..
I'm not a perl guy however so I'll have to guess what
you want..
Here is what I get.
You are trapping sigchld.
You are reading a plaintext file that contains the names
and passwords of users to add exec'ing adduser, exec'ing passwd, then su to the newuser and adding a maildir. Right so far?

I don't know how much of this you want in expect.
You could do it all, part or parts..


#!/usr/bin/expect

set timeout 3000
#don't wait forever on processes terminate after a while.
exp_internal 1
#debugging, comment out if you want.
log_user 0
#don't echo every thing.
set ctr 0
#counter var
#do your trap
trap {
send_user &quot;Caught signal [trap -name]\n&quot;
send_user &quot;Ignoring..\n&quot;
} SIGCHLD

#open file..save error in err_f
if {![catch {set fd [open &quot;smusers.txt&quot; r]} err_f]} {
#load file read into variable contents
set contents [read $fd]
}
close $fd
#close your file after array loaded

#start processing
if {[info exists contents]} {
foreach line [split $contents \n] {
#create vars for the parsed user and pass
regexp &quot;^(.*?):.*.*?)$&quot; $line user pass
#spawn passwd
spawn -noecho passwd [string trim $user]
set id $spawn_id

expect {
#look for passwd prompt
-re &quot;.*(P|p)assword.*&quot; {
#automate the process
send &quot;[string trim $pass]\r&quot;
#secondary prompt
expect -re &quot;.*enter new password.* &quot;
send &quot;[string trim $pass]\r&quot;
#passwd confirmation
expect -re &quot;.*assword.*ange.*&quot;
send_user &quot;All done for $user\n&quot;
#not really necessary with passwd
catch {close $id}
}
#end of passwd spawn, alert user
eof { send_user &quot;Caught passwd end for [incr ctr] iteration\n&quot;
send_user &quot;$expect_out(buffer)\n&quot;
}
} ;#end expect
} ;#end for loop
} else {
#errors.
error &quot;Could not process array: $err_f occurred.&quot;
} ;#endif

 

[marsd]

A few corrections and comments..
The regexp line will definitely have to be tweaked
depending on your file content and format, those are perl
regexps I notice now with the .*?, I don't know how tcl
will look at these...Also since tcl's regexp command
looks at all matches, first match in parens, second in
parens, etc.. the regexp should look like:
regexp &quot;(pat)patstuff(pat)&quot; $line all user pass

A suggestion:
Check for autoexpect on your machine and then run a sample
passwd change for a user and look at the output of the
autoexpect script to see how he interaction looks to expect.
> autoexpect passwd username

Expect will talk to you about what it sees and create a script for you, just like the *nix script command.

If you have any questions or need help write back.
Good Luck