Tie::Handle(3pm)

NAME

Tie::Handle - base class definitions for tied handles

SYNOPSIS

    package NewHandle;
    require Tie::Handle;
     
    @ISA = (Tie::Handle);
     
    sub READ { ... }            # Provide a needed method
    sub TIEHANDLE { ... }       # Overrides inherited method
         
     
    package main;
    
    tie *FH, 'NewHandle';

DESCRIPTION

This module provides some skeletal methods for handle-tying classes. See the perltie manpage for a list of the functions required in tying a handle to a package. The basic Tie::Handle package provides a new method, as well as methods TIESCALAR, FETCH and STORE. The new method is provided as a means of grandfathering, for classes that forget to provide their own TIESCALAR method.

For developers wishing to write their own tied-handle classes, the methods are summarized below. The the perltie manpage section not only documents these, but has sample code as well:

TIEHANDLE classname, LIST

The method invoked by the command tie *glob, classname. Associates a new glob instance with the specified class. LIST would represent additional arguments (along the lines of the AnyDBM_File manpage and compatriots) needed to complete the association.

WRITE this, scalar, length, offset

Write length bytes of data from scalar starting at offset.

PRINT this, LIST

Print the values in LIST

PRINTF this, format, LIST

Print the values in LIST using format

READ this, scalar, length, offset

Read length bytes of data into scalar starting at offset.

READLINE this

Read a single line

GETC this

Get a single character

DESTROY this

Free the storage associated with the tied handle referenced by this. This is rarely needed, as Perl manages its memory quite well. But the option exists, should a class wish to perform specific actions upon the destruction of an instance.

MORE INFORMATION

The the perltie manpage section contains an example of tying handles.