04-24-2013
Quote:
Originally Posted by
rbatte1
Out of curiosity, why is
eval considered
evil .
Because it will evaluate
any shell syntax you put into it, even things you didn't intend it to.
Imagine your program prompts for a user name, and someone types in
$(rm -Rf ~/). Then that variable gets fed into an
eval...
It is very, very difficult to make eval secure from this. Not impossible, but very hard. Much doublethink is required.
Further, it's often used by beginning programmers as a bridge or shoehorn when they don't know a better way to solve a problem.
Last edited by Corona688; 04-24-2013 at 01:34 PM..
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LEARN ABOUT DEBIAN
padre::task::eval
Padre::Task::Eval(3pm) User Contributed Perl Documentation Padre::Task::Eval(3pm)
NAME
Padre::Task::Eval - Task for executing arbitrary code via a string eval
SYNOPSIS
my $task = Padre::Task::Eval->new(
prepare => '1 + 1',
run => 'my $foo = sub { 2 + 3 }; $foo->();',
finish => '$_[0]->{prepare}',
);
$task->prepare;
$task->run;
$task->finish;
DESCRIPTION
Padre::Task::Eval is a stub class used to implement testing and other miscellaneous functionality.
It takes three named string parameters matching each of the three execution phases. When each phase of the task is run, the string will be
eval'ed and the result will be stored in the same has key as the source string.
If the key does not exist at all, nothing will be executed for that phase.
Regardless of the execution result (or the non-execution of the phase) each phase will always return true. However, if the string eval
throws an exception it will escape the task object (although when run properly inside of a task handle it should be caught by the handle).
METHODS
This class contains now additional methods beyond the defaults provided by the Padre::Task API.
COPYRIGHT & LICENSE
Copyright 2008-2012 The Padre development team as listed in Padre.pm.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
The full text of the license can be found in the LICENSE file included with this module.
perl v5.14.2 2012-06-27 Padre::Task::Eval(3pm)