Tie::Handle - base class definitions for tied handles
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';
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.
The perltie section contains an example of tying handles.
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.
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