Perl pursue simple to solve a general problem with a few lines of code it is completed . Issue a little bit more complex code can not be more than one screen . In software testing , Perl is usually very important role. Generally a common function library should test several documents in ten , or even more , containing up to thousands of customizable features . These functions will run in the main function , the variable number is called. Almost say that everything is done by an automated process Perl yourself, its powerful and visible in today's period of rapid development of computer technology continues to play an important role.
Initially as a kind of Unix Perl scripting language design , but it has long been ported to other operating systems in the majority . Because Perl can run almost anywhere, so Perl can be said that most of today's portable programming environment. To write portable C / C + + program , you have to add a lot of # ifdef label in the program to distinguish between different systems. To write portable Java programs , you must understand the characteristics of each new Java implementation . To write portable shell, you may want to remember the syntax of each command on each operating system , good luck when you may be able to find some common things. And in order to write portable Visual Basic program , you only need to "transplant " There is a more flexible definition of it.
Perl is very pleased that avoids all of these problems , while retaining many of the advantages of these languages , as well as some of their characteristics. Perl characteristics from many aspects : its feature set tools , Perl creative community , the environment and the open source movement . However , many of these features are mixed stuff ; Perl complex life experience , as it is always the object of different aspects of the advantages , not weakness. Perl is a " scapegoat me " language. If you feel yourself into a mess among the very desire for freedom , then please use Perl.
Perl is cross-cultural . Perl is largely due to the explosive growth of the former Unix systems programmer who desire to do more than they want to take something from their " home ." For them , Perl is portable Unix culture distiller , is " not a workable option " oasis in the desert . From another perspective , Perl can also be run from another direction : Windows web designers usually very happy to find that their Perl programs can run without modification on Unix servers.
Although very popular Perl programmers and web designers in the middle of the system , it is because they first discovered Perl, Perl can be used more widely. Starting with Perl earliest text processing language , it has evolved into a very complex , general-purpose programming language , and a complete development environment, including a debugger , regulators, cross-references , compilers, libraries, grammar tips editor, and all the other "real" programming language has the hook , as long as you need . These things are so that we could deal with something difficult problem , and many other languages can do this. Perl Perl because it 's becoming a never keep it simple things simple since lost other features.
Because Perl is both powerful and easy to use , so it is widely used in aspects of daily life , from aerospace engineering to molecular biology, from mathematics to linguistics, from graphics to document processing and management operations from the database to the network . Many people use Perl for rapid conversion to deal with those difficult to analyze large quantities of data , or whether you are processing DNA sequences , web , or pig belly future does not matter. In fact there is a joke in the Perl community is the next stock market crash is very likely to be the guy to write the script inside which there is a bug caused ( however , the music point of view is that any are still unemployed stock analysts can still have skills ) .
There are many reasons for the success of Perl . Perl name long before the emergence of open source software has been a successful open source project. Perl is free, and will always go freely . You can use Perl on any occasion , just to comply with a very liberal copyright on it. If you want to engage in commercial activities and the use of Perl, then use the grindstone. You can embed Perl you write commercial software without the need to pay any fees and no restrictions. If you run into a Perl community can not solve the problem, and that you still have a last resort : the source code itself. Perl community will not rent you their trade secrets under the "upgrade" camouflage. And Perl community is not " closed ", but will not let you alone.
Perl is a free software which point it will undoubtedly be helpful . Yet that is not enough to explain the phenomenon of Perl , because many free software package failed to flourish. Perl is not only freedom , but also fun. People feel that they can be creative in Perl , because they have the freedom of expression : they can choose to optimize computer speed or speed optimization for programmers , is lengthy or simple, is to choose the readability or maintainability, or multiplexed , portability , acceptance and teach and so on. If you enter a fuzzy Perl game , and even that ambiguity do optimization.
Perl can give you all of these freedoms , since it is a language with a split personality . Perl is also very simple and very rich language. Perl brought good idea from somewhere else , and then put them inside the frame to install and easy to use . For those who just love it , Perl is a practical extraction and report language (Practical Extractoin and Report Language). For those who love it , it is the metamorphosis of electronic waste producers (Pathologically Electric Rubbish Lister). In a few people's eyes , Perl is meaningless repetition . But the world needs a little redundant . Streamlining advocates always want things separated . And we always try to merge them together.
The reason is simple Perl language for many reasons . If you do not need to know any special instructions you can compile the Perl program, just think of it as a batch or shell script can be executed . Perl types and structures are easy to use and understand. Perl is no any restrictions on your data , you may want to strings and arrays on how long how long ( as long as you have enough memory ) , and they will grow automatically. Perl does not force you to learn new syntax and semantics , Perl change from many of you are already familiar with other languages ( such as C, awk, BASIC and Python, English, Greek , etc. ) borrowed syntax. In fact, any programmer can read it from meaning to write good Perl code segment .
The most important thing is , you do not first learn all the things Perl can begin to write useful programs . You can write a small Perl program . You can also write a Perl program that as a child , guaranteed not to laugh at you . Or more accurately , the child will never laugh creative work . Perl where many ideas are borrowed from the natural language , one of the best view is as long as you can clearly express their meaning , then you can use a subset of these languages . Perl culture can accept any member of proficiency. We will not put you behind a language police. If your boss does not fire you , but your Perl script can complete the work , then it is "right" .
Perl is very simple, but it is still a very rich language features , if you want to use those features , then you have to learn something. This is also the problem becomes simple tuition. Although you want to do things to absorb all Perl will take some time , but when you need these features you will be very happy to find that Perl can already do these things.
Because Perl inheritance , even if it is only used when the data summarized language also has extensive features , Perl outset designed to browse files, scanned text and generate a lot of dynamic data and print out the data well formatted reports . But then it became popular Perl , so it became possible operating file system, process management, database management , conduct C / S programming and secure programming , web information management and can even be oriented object-oriented and functional programming language. And these features are not only in the Perl side, each new exchange functions and other things very well , do not forget Perl is designed from the outset to glue language.
And not just Perl can glue it's own characteristics. Perl module is designed to be extended with the language . You can use Perl to quickly design , write, debug, and deploy Perl applications, and you can easily extend these applications when needed . You can embed Perl in other languages, and you can also embed other languages in Perl . By module input mechanism , you can put these external expansion features as built- in Perl . Those facing external libraries like in Perl remains inside the object-oriented features .
Perl assist you in many other ways. And strict implementation of a command file commands and shell scripts is different , Perl first fast compile your program into an internal format. Like any other compilers , this time also a variety of optimization , while the problems encountered any feedback to you. Once satisfied with Perl compiler front-end of your program, it took these intermediate code interpreter to execute ( or to another can generate C code or byte module backend ) . Sounds complicated, but Perl compiler and interpreter working efficiency is very high, we compile - run - almost all of the revision process in seconds . Perl plus many other development features , this rapid role reversal is suitable for rapid prototyping . Then with the maturity of your program , you can gradually tighten the nut tight to reduce undisciplined enhance discipline. If you do well , Perl also help you this favor .
Perl can also help you write more secure programs. In addition to other languages beyond the typical security interface , Perl through a mechanism of tracking data to provide you with accident prevention safety error protection , so that you can prevent it before the disaster occurred . Finally , Perl can also set up a special protection every segment of unknown origin who run Perl code , in order to prevent dangerous operation .
However , to say a little paranoid , Perl help you most of the content and Perl does not have anything to do, but about people and use Perl . Frankly, it can be said that the Perl community on the planet 's most enthusiastic people. If there is so little movement Perl religious , then this is the core of it . Larry hopes Perl community like a small piece of paradise as running, now it seems his wish is basically true. We also ask you to do this to make their own efforts.
Perl were strong because there are CPAN, CPAN above, there are numerous open-source modules from scientific computing to the desktop application to various aspects of the network , such as a large number of modules. And now the world there are still countless people add modules to the top. If you want to use Perl to achieve a certain function , do not do it themselves, in the search for a search CPAN above , will get most of the existing results. CPAN ("the Comprehensive Perl Archive Network" Comprehensive Perl Archive Network ) is to find something related to any Perl central warehouse . It contains the collected wisdom of the entire Perl community : hundreds of Perl modules and scripts , the equivalent of several books of documents, and the entire Perl release. If something is written in Perl , and this stuff is useful and is free, then it is very likely on CPAN.
Because Perl 's flexibility and "excessive" redundant syntax , also won the write only of "reputation " because many Perl code is hard to read , to achieve the same function code ten times the length can vary . But Perl code can also be written as elegant like Python or Ruby and other languages.