Current Perl documentation can be found at perldoc.perl.org.
Here is our local, out-dated (pre-5.6) version:
If perl was installed correctly, and your shadow library was written
properly, the getpw*() functions described in the perlfunc manpage should in theory provide (read-only) access to entries in the shadow
password file. To change the file, make a new shadow password file (the
format varies from system to system - see passwd(5) for specifics) and use
pwd_mkdb(8) to install it
(see pwd_mkdb(5) for more details).