This special line is a hint to Unix to use the Perl interpreter to executethe code in this file. The interpreter makes one pass of the file to analyze it and if thereare no syntax or other obvious errors, the interpreter runs the Perl code.There is no "main" function - the interpreter just executes the statementsin the file starting at the top.įollowing the Unix convention, the very first line in a Perl file usuallylooks like this. On Unix, the Perlinterpreter is called "perl" and you run a Perl program by runningthe Perl interpreter and telling it which file contains your Perl program. Thisstructure makes your edit-run-debug cycle nice and fast. You edit the text of your Perl program,and the Perl interpreter reads that text file directly to "run" it. Running PerlA Perl program is just a text file. Also,in versions 5 and 6, Perl has accumulated more sophisticated features whichare not covered here. The terse styleis mentioned briefly in the Terse Perl section. I write Perl code in a boring, straightforward way whichtends to spell out what it's actually doing step by step. There's something satisfying aboutreducing a whole computation down to a single line of dense code. Warning: My Boring Perl StylePerl is famous for allowing you to write solutions to complex problemswith very short, terse phrases of code. On the other hand, in my opinion, Perl'seasy-going style makes it less appealing for large projects where I wouldrather use Java. Perlcode is also robust Perl programs can have bugs, but they will not crashrandomly like C or C++ programs. With Perl,you are not locked in to any particular vendor or operating system.
PERL ARRAY SIZE PORTABLE
Perl code is very portable - I frequently move Perl programsback and forth from the Mac to various Unixes and it just works. If I need a 23 lineprogram to get some task done, I can write it in Perl and be done in 3minutes.
However, Perl's quick, informal stylemakes it attractive for all sorts of little programs. Perl NichePerl is probably best known for text processing - dealing with files,strings, and regular expressions.
PERL ARRAY SIZE ARCHIVE
A culture has built up around Perl wherepeople create and give away modules, documentation, sample code, and athousand other useful things - visit the Comprehensive Perl Archive Network(CPAN),, or see the amazing range of Perl material available. What Is Perl?Perl is a free, open source programming language created by Larry Wall.Perl aims for adjectives like "practical" and "quick" and not so much wordslike "structured" or "elegant". This document is freeto be used, reproduced, or sold so long as this paragraph and the copyrightare clearly reproduced. This is document #108 in the Stanford CS Education Library - see this and other free educational CS materials.
PERL ARRAY SIZE FOR FREE
This document is available for free inthe spirit of engineering goodwill - that success is not taken, it isearned. The coverage is pretty quick, intended for peoplewith some programming experience. Perl has manyfeatures, but you can get pretty far with just the basics, and that's whatthis document is about. Essential Perl Essential PerlThis document is a quick introduction to the Perl language.
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