command line parameters

Q:
I would like to pass in some variables via the command line. For example,
I want to be able to run the program the following way.

perl program.pl -u my_username -p my_password

Where the -u switch signifies the following string is the user name and
the -p switch is for their password. Can you help me on how to do this?
A:
it is simple. The command line parameters are in the array @_ thus

$_[0] is '-u'
$_[1] is 'my_username'

and so on

regards,
Peter
Q:
Thanks for the quick answer. But what about if I have a bunch of
variables to pass in and I don't want to let the user pass it in any order
on the command line.

ie.
perl program.pl -u username -p password -O org_id -G group_id

say I want the user to be able to type perl program.pl -u username -O
org_id -p password -G group_id

etc, etc.????

Thanks!

A:
This does not make any difference. The array @_ will contain the command
line parameters in the order the user specifies the parameters.

All you need in a small loop that checks them. For example:

$i = 0;
while($_[$i]){
$password = $_[$i+1] if $_[$i] eq '-p';
$username = $_[$i+1] if $_[$i] eq '-u';

... and so on ...

$i += 2;
}