oracular (3) Tie::Handle.3perl.gz

NAME

       Tie::Handle - base class definitions for tied handles

SYNOPSIS

           package NewHandle;
           require Tie::Handle;

           @ISA = qw(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 perltie 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 "TIEHANDLE", "PRINT", "PRINTF" and "GETC".

       For developers wishing to write their own tied-handle classes, the methods are summarized below. The
       perltie 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 AnyDBM_File 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

       CLOSE this
           Close the handle

       OPEN this, filename
           (Re-)open the handle

       BINMODE this
           Specify content is binary

       EOF this
           Test for end of file.

       TELL this
           Return position in the file.

       SEEK this, offset, whence
           Position the file.

           Test for end of file.

       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 perltie section contains an example of tying handles.

COMPATIBILITY

       This version of Tie::Handle is neither related to nor compatible with the Tie::Handle (3.0) module
       available on CPAN. It was due to an accident that two modules with the same name appeared. The namespace
       clash has been cleared in favor of this module that comes with the perl core in September 2000 and
       accordingly the version number has been bumped up to 4.0.