perldoc > Tie::Handle

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📖 NAME

Tie::Handle - base class definitions for tied handles

🚀 Quick Reference

Use Case	Command	Description
Create a tied handle class	package NewHandle; require Tie::Handle; @ISA = qw(Tie::Handle);	Subclass Tie::Handle to provide custom handle methods
Tie a handle to a class	tie *FH, 'NewHandle';	Associate a glob with a class implementing tied handle methods
Read from a tied handle	read FH, $buf, 1024;	Use the READ method of the tied class
Write to a tied handle	print FH "data";	Use the PRINT method of the tied class

📝 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.
• 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.

📖 NAME 🚀 Quick Reference 📝 SYNOPSIS 📋 DESCRIPTION 📚 MORE INFORMATION 🔄 COMPATIBILITY