Perl难学吗?
Perl不但容易上手,也容易继续学下去。它看起来和大多数您可能已接触过的语言一样。所以如果您只写过 C 程式、或 awk script、shell script,或甚至只是 Excel的 macro(巨集),您已经在半路了。
大多数的任务只需要 Perl语言的一小部分即可完成。发展 Perl程式的座右铭即是「不只一种方法可以达到」(TMTOWTDI; There's More Than One Way To Do It, 有时读作「堤姆投迪」)。因此,Perl的学习曲线是既平(易学)且长的(如果您要的话,有一大堆够您学的)。
Perl程式应算是 program还是 script?
都无所谓。
按标准术语来讲,program指已经由编译程序编译好、转为机器码,可多次执 行的程式;而 script则是每次执行时都必须透过一个解译程式来解译。然而,Perl程式严格说来,既非编译 (compiled) ,亦非解译式 (interpreted);因 Perl程式可转译成位元码形式存在(可说是某种 Perl虚拟机器 [virtual machine]),或转译为完全不同的语言,如 C或组合语言。所以光看原始码很难 说它到底是替纯解译器、或是 parse-tree解译器、位元码解译器,还是纯码编译器而写;因此这题很难给它一个确切的答案。
What is Perl?
Perl is an interpreted high-level programming language developed by Larry Wall. According to Larry, he included in Perl all the cool features found in other languages and left out those features that weren't so cool.
Perl has become the premier scripting language of the Web, as most CGI programs are written in Perl. However, Perl is widely used as a rapid prototyping language and a "glue" language that makes it possible for different systems to work well together. Perl is popular with system administrators who use it for an infinite number of automation tasks.
Perl's roots are in UNIX but you will find Perl on a wide range of computing platforms. Because Perl is an interpreted language, Perl programs are highly portable across systems.
Finally, Perl is more than a programming language. It is a part of the Internet culture. It is a very creative way of thinking about almost anything.
What is Perl?
Perl is a high-level programming language with an eclectic heritage written by Larry Wall and a cast of thousands. It derives from the ubiquitous C programming language and to a lesser extent from sed, awk, the Unix shell, and at least a dozen other tools and languages. Perl's process, file, and text manipulation facilities make it particularly well-suited for tasks involving quick prototyping, system utilities, software tools, system management tasks, database access, graphical programming, networking, and world wide web programming. These strengths make it especially popular with system administrators and CGI script authors, but mathematicians, geneticists, journalists, and even managers also use Perl. Maybe you should, too.
Perl history in brief, by Larry Wall:
Perl 0 introduced Perl to my officemates.
Perl 1 introduced Perl to the world, and changed /\(...\|...\)/ to
/(...|...)/. \(Dan Faigin still hasn't forgiven me. :-\)
Perl 2 introduced Henry Spencer's regular expression package.
Perl 3 introduced the ability to handle binary data (embedded nulls).
Perl 4 introduced the first Camel book. Really. We mostly just
switched version numbers so the book could refer to 4.000.
Perl 5 introduced everything else, including the ability to
introduce everything else.