Tie::Scalar

See the current Perl documentation for Tie::Scalar.

Here is our local, out-dated (pre-5.6) version:

Tie::Scalar, Tie::StdScalar - base class definitions for tied scalars

    package NewScalar;
    require Tie::Scalar;
     
    @ISA = (Tie::Scalar);
     
    sub FETCH { ... }           # Provide a needed method
    sub TIESCALAR { ... }       # Overrides inherited method
         
     
    package NewStdScalar
    

    

This module provides some skeletal methods for scalar-tying classes. See
perltie 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  perltie. 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 perltie 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 AnyDBM_File and compatriots) needed to complete the association.

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 perltie section uses a good example of tying scalars by associating process IDs
with priority.