Tie::Scalar(3) Perl Programmers Reference Guide Tie::Scalar(3)NAME
Tie::Scalar, Tie::StdScalar - base class definitions for
tied scalars
SYNOPSIS
package NewScalar;
require Tie::Scalar;
@ISA = (Tie::Scalar);
sub FETCH { ... } # Provide a needed method
sub TIESCALAR { ... } # Overrides inherited method
package NewStdScalar;
require Tie::Scalar;
@ISA = (Tie::StdScalar);
# All methods provided by default, so define only what needs be overridden
sub FETCH { ... }
package main;
tie $new_scalar, 'NewScalar';
tie $new_std_scalar, 'NewStdScalar';
DESCRIPTION
This module provides some skeletal methods for scalar-
tying classes. See the perltie manpage for a list of the
functions required in tying a scalar to a package. The
basic Tie::Scalar package provides a new method, as well
as methods TIESCALAR, FETCH and STORE. The Tie::StdScalar
package provides all the methods specified in the perltie
manpage. It inherits from Tie::Scalar and causes scalars
tied to it to behave exactly like the built-in scalars,
allowing for selective overloading of methods. The new
method is provided as a means of grandfathering, for
classes that forget to provide their own TIESCALAR method.
For developers wishing to write their own tied-scalar
classes, the methods are summarized below. The the perltie
manpage section not only documents these, but has sample
code as well:
TIESCALAR classname, LIST
The method invoked by the command tie $scalar,
classname. Associates a new scalar instance with the
specified class. LIST would represent additional
arguments (along the lines of the AnyDBM_File manpage
and compatriots) needed to complete the association.
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Tie::Scalar(3) Perl Programmers Reference Guide Tie::Scalar(3)
FETCH this
Retrieve the value of the tied scalar referenced by
this.
STORE this, value
Store data value in the tied scalar referenced by
this.
DESTROY this
Free the storage associated with the tied scalar
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 the perltie manpage section uses a good example of
tying scalars by associating process IDs with priority.
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