Tie::Handle (3)

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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 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.