Any good distribution of Perl will come with copious amounts of documentation installed. From a command line, simply type "perldoc perlfaq" to start reading the FAQ.
With that in mind, your problem can be broken down into several steps:
In reply to Re: Passwd file
by chromatic
in thread Text file (Passwd file) record editing
by Anonymous Monk
| For: | Use: | ||
| & | & | ||
| < | < | ||
| > | > | ||
| [ | [ | ||
| ] | ] |