This should please the comp.lang.c old timers: 
use strict;
use warnings;
use 5.010;

BEGIN {
    &Internals::SvREADONLY(\undef, 0);
    ${\undef} = "Demons are coming out of my nose!";
};

[download]
I wonder if you can redefine other read-only values? I could not get the following to work. 
BEGIN {
    &Internals::SvREADONLY(\'blue', 0);
    ${\'blue'} = 'turtle';
    
    &Internals::SvREADONLY(\5, 0);
    ${\5} = 5.000000000001;
    
};

[download]
(I have no idea why you would want to do this apart from JAPH or intentional sabotage)

In reply to Re: Perl allows you to change the definition of false to make it true. (And vice versa.) by Anonymous Monk
in thread Perl allows you to change the definition of false to make it true. (And vice versa.) by tobyink

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