All the documents linked below should also be available on your system (provided you've got a full perl base install) using "perldoc NAME" (for full manual sections) or "perldoc -f NAME" (for functions) from the command line, where NAME is the text of the link. See also "perldoc perltoc"

How to use hashes (and arrays and scalars), see perldata.

@_ and $_ are the default array and scalar. For instance shift and pop without arguments modify @_, and print without arguments prints the current value of $_.

@_ also gets set with the arguments to the current subroutine and $_ is used as a general single argument. See perlsub and perlvar.