Simple .NET/ASP.NET PDF document editor web control SDK

Computers are supposed to be precise, but anyone with basic arithmetic skills will know that 10 divided by 3 is 3.33 recurring, rather than 3! The reason for the curious result is that, by default, Ruby assumes a number such as 10 or 3 to be an integer a whole number. Arithmetic with integers in Ruby gives integer results, so it s necessary to provide Ruby with a floating point number (a number with decimal places) to get a floating point answer such as 3.33. Here s an example of how to do that:

winforms pdf 417 reader, winforms qr code reader, winforms upc-a reader, winforms data matrix reader, winforms ean 128 reader, winforms ean 13 reader, itextsharp remove text from pdf c#, replace text in pdf c#, winforms code 39 reader, c# remove text from pdf,

Unobvious outcomes such as these make testing not only a good learning tool, but an essential process in larger programs. That s enough of the errors for now though. Let s make something useful!

9

Although it s possible to check whether data is tainted and perform preventative actions to clean it up, a stronger form of protection comes with Ruby s safe levels. Safe levels

allow you to specify what features Ruby makes available and how it should deal with tainted data. The current safe level is represented by the variable $SAFE. By default, $SAFE is set to 0, providing the lowest level of safety and the highest level of freedom, but four other safe modes are available, as shown in Table 11-1.

>>> from math import sqrt >>> exec "sqrt = 1" >>> sqrt(4) Traceback (most recent call last): File "<pyshell#18>", line 1, in sqrt(4) TypeError: object is not callable: 1 Well, why would you do something like that in the first place, you ask The exec statement is mainly useful when you build the code string on the fly. And if the string is built from parts that you get from other places, and possibly from the user, you can rarely be certain of exactly what it will contain. So to be safe, you give it a dictionary, which will work as a namespace for it.

The verbal and visual variations that you can create using BBP are literally endless This chapter shows you more examples of BBP in action as it is applied to a wide range of topics and purposes, showing what a presentation might look if you were to: Introduce a case to jurors in an opening statement with The Trial Keep your team on track toward completing a project with The Plan Summarize your market research ndings to your clients with The Analysis Update and gain the support of your boss for your activities with The Report Teach your students about a new topic with The Class Sell the services of your company to a client with The Pitch.

0 1 2

No restrictions. This is the default safe level. Potentially unsafe methods can t use tainted data. Also, the current directory is not added to Ruby s search path for loading libraries. The restrictions of safe level 1, plus Ruby won t load any external program files from globally writable locations in the filesystem. This is to prevent attacks where hackers upload malicious code and manipulate existing programs to load them. Some potentially dangerous methods are also deactivated, such as File#chmod, Kernel#fork, and Process::setpriority. The restrictions of level 2, plus newly created objects within the program are considered tainted automatically. You also cannot untaint objects. The restrictions of level 3, plus nontainted objects created prior to the safe level being set cannot be modified. You can use this to set up an execution environment in a lower safe mode, and then provide a way to continue execution while protecting the original objects and environment.

To change the safe level, simply set $SAFE to whichever safe level you want to use. Do note, however, that once you set the safe level, you can only increase the safe level and not decrease it. The reason for this is that allowing the safe level to be reduced would make it possible for eval-ed code to merely turn down the safety level and cause havoc!

Because of space limitations, the examples in this chapter show selected portions of story templates, storyboards, and slides, focusing primarily on the critical Act I, Call to Action, and Key Point slides rather than on the Explanation and Detail slides that will contain your own speci c photos, charts, graphs, screen captures, and diagrams Every presentation was built using the same process in this book, but each looks and feels very different Likewise, your own presentations will re ect your own understanding of your speci c audiences that determines the words you write in the story template, the graphics you add to the storyboard, and the way you deliver the experience.