tie

tie 
variable
, 
classname
, 
list

Binds a variable to a package class, classname , that will provide the implementation for the variable. Any additional arguments ( list ) are passed to the "new" method of the class (meaning TIESCALAR , TIEARRAY , or TIEHASH ). Typically these are arguments such as might be passed to the dbm_open(3) function of C, but this is package-dependent. The object returned by the "new" method is also returned by the tie function, which can be useful if you want to access other methods in classname . (The object can also be accessed through the tied function.)

A class implementing a hash should provide the following methods:

TIEHASH $class, 
LIST

DESTROY $self
FETCH $self, $key
STORE $self, $key, $value
DELETE $self, $key
EXISTS $self, $key
FIRSTKEY $self
NEXTKEY $self, $lastkey

A class implementing an ordinary array should provide the following methods:

TIEARRAY $classname, 
LIST

DESTROY $self
FETCH $self, $subscript
STORE $self, $subscript, $value

A class implementing a scalar should provide the following methods:

TIESCALAR $classname, 
LIST

DESTROY $self
FETCH $self, 
STORE $self, $value

Unlike dbmopen , the tie function will not use or require a module for you - you need to do that explicitly yourself.