All Posts Tagged Tag: ‘perl’
In what could be a bad day for United Kingdom pen testers, stress testers, and other systems security folks, the UK is getting ready to ban the creation and distribution of tools that could be used by hackers. This generally unpleasant concept could make it not only impossible to create the next nessus or nmap by anyone in the UK, it could also send them to jail for distributing the tools they make as well.
This ought to set back UK computer security by decades.
I recently did a little web based Service Schedule. This is something that gets its data from another program: in other words, the details of what will be serviced and when are supplied by that program; this web based app validates things, assigns technicians and does some other things that the first program doesn’t.
In the review copy I read, there still were some unfortunate typos that might confuse someone completely new to Perl. I hope those will be fixed before the actual publication. None of them bothered me, but they could be bad for someone starting with no experience at all.
I’ve been using http://groups-beta.google.com/ for Newsgroup posting for a while now. It’s convenient for me because of my nomadic life style where I have different ISP’s and often different machines with varying OSes. Google only needs a browser, and they aren’t overly fussy about that, either.
When you strip away all the layers of marketing hype and industry jargon, Microsoft’s Component Object Model (COM) is simply a technology that allows you to create an object in the language of your choice, and to make the functionality of that object available to any other object, or any other application, regardless of the language that the other object or application is written in.
Most computer users, especially software engineers, have had a need to modify multiple files to either add a line of text, modify a line of text, or completely remove a line of text. The problem is that there never seems to be a piece of software out there that can help you with this problem. Some programs let you get close to doing what you want but in my experience none ever let you do exactly what you want; so a few hours are spent opening each file and editing them manually.
MRTG is the most popular open source performance measuring tool being used around the world today. While MRTG is open source, it has been widely adopted by major companies everywhere who use it to measure network performance and adherence to SLAs, among other things. For an interesting snapshot of who is using MRTG, and for what purpose, go to MRTG’s “Where, What, How” page and have a look at some of the interesting things MRTG is being used to track. Although MRTG started out as an application to measure network performance on routers (MRTG stands for “Multi Router Traffic Grapher”), it is being used today to graph everything from traffic jams in the Netherlands to the local temperature in Wroclaw. If you can provide a numeric value to MRTG, it can produce a graph of it.
Perl folk seem not to like Python, at least not at first glance. It’s easy to understand why: the languages serve similar purposes, but have annoyingly different syntax and structure. There have been converts, though, and Eric S. Raymond’s experiences are probably not atypical.
Perl has wonderful I/O capabilities. I’m only going to cover input here: reading from files or standard input. There are two ways to do that (actually a lot more than two, but this is supposed to be introductory material): you can open a specific file, or you can pass files on the command line and either open them individually or just ignore the whole thing and pretend everything is coming from STDIN.
Recently I had a project that required a number of different programs that will mostly run all the time, but need to be restarted now and then with different parameters. Normally, the first thing I think of for a program that runs constantly is inittab or svc (daemontools). The svc facility is the more flexible of the two, and will be what I’ll use in the final design, but in the “thinking” stages I played with using a Perl program launcher and controller.
An oversimplified introduction to sockets
Sockets are a mechanism that allows programs to communicate, either on the same machine or across a network. The way it works is pretty simple: Each machine on a network is identified by some address. In this tutorial we will talk about tcp/ip networking, so by network address we mean an IP address. (like 192.168.4.4) Apart from the IP address that specifies a machine, each machine has a number of ports that allow handling multiple connections simultaneously.
Sorting is a commonly needed operation in all kinds of programs. Luckily, for us perl programmers, perl provides a very simple yet extremely powerful mechanism to accomplish any sort you might think of. This article is about teaching the novice programmer how to sort lists of things, while showing to the more experienced folks certain techniques and ideas that could be new to them if they are migrating from a different language.
Perl (Practical Extraction and Report Language) is a predominately Unix driven program. There are interpreters for all the major (and minor) OS’s but to run them locally you have to have Unix, Linux, or Mac OS X. If you want to get the interpreter for Classic it is available for free at http://www.macperl.com. You can still follow what we will be doing, just ignore all the X mumbo jumbo.
Regular expressions are hard to write, hard to read, and hard to maintain. Plus, they are often wrong, matching unexpected text and missing valid text. The problem stems from the power and expressiveness of regular expressions. Each metacharacter packs power and nuance, making code impossible to decipher without resorting to mental gymnastics.
Object Oriented Programming in Perl
Most people are not aware of the fact that Perl has support for object-oriented programming. If you’ve used another object-oriented programming language such as Java or C++ or been exposed to object-orientation then object oriented programming in Perl is nothing like that. To do real useful object-oriented programming in Perl you only need to use three simple rules as put forth by Larry Wall in Object Oriented Perl .
RSS is quickly becoming the standard choice for delivering syndicated web content. Have you ever wondered how some of the large content sites deliver their headlines? Or, have you ever wanted to display news headlines, but didn’t want to display the standard “Content Provided By…” info? Or, have you ever wanted to syndicate your own content? RSS may be the answer you’ve been looking for.
I know that you all want to get rid of Perl Scripts because of their complexity and the fact that Perl is not an easy language to learn. With the introduction of PHP version 4.2, PHP has started supporting a new SAPI (Server Application Programming Interface) called CLI (Command Line Interface). This facility was introduced to help developers create small shell application (scripts) with PHP, meaning that you can kiss Perl goodbye forever!
At the heart of every language is a core set of ideals that give the language its direction and purpose. If you really want to understand the choices that language designers make–why they choose one feature over another or one way of expressing a feature over another–the best place to start is with the reasoning behind the choices.
This article will show you how to do two things:
1. Round numbers to the nearest hundredth, with two digits following the decimal point. This can be useful when displaying prices or the totals of orders.
2. Insert commas between every third digit (right to left) for numbers 1000 and larger. This can make numbers easier to read.
One of the most common categories of questions on the SOAP::Lite mailing list is how to get Perl SOAP applications to work with .NET services. It’s not that Perl and SOAP::Lite are not suited to the job, but rather that there are easy traps to fall into. Add to that the fact that .NET has its own distinct philosophy toward applications, and the confusion is understandable. This article will cover some of the most common traps and considerations that trip up Perl developers.