


Tie::Handle(3p)  Perl Programmers Reference Guide Tie::Handle(3p)


NAME
       Tie::Handle, Tie::StdHandle  - 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 "TIEHANDLE", "PRINT", "PRINTF" and "GETC".

       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, class-
           name". Associates a new glob instance with the speci-
           fied class. "LIST" would represent additional argu-
           ments (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 off-
           set.

       READLINE this
           Read a single line




2001-05-24                 perl v5.6.1                          1





Tie::Handle(3p)  Perl Programmers Reference Guide Tie::Handle(3p)


       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 ref-
           erenced by this.  This is rarely needed, as Perl man-
           ages 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.

COMPATIBILITY
       This version of Tie::Handle is neither related to nor com-
       patible 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.















2001-05-24                 perl v5.6.1                          2


