![]() The only thing you need to know is that you never insert commas or spaces into numbers in Perl. Numbers are easy we’ve all dealt with them. There are two basic data types in Perl: numbers and strings. print "This is " print "two statements.\n" print "But this ", ![]() Statements don’t need to be on separate lines there may be multiple statements on one line or a single statement can be split across multiple lines. print "This is a single statement." Ī Perl program consists of statements, each of which ends with a semicolon. It takes a list of things to output as its parameters. You use it to display things on the screen or to send information to a file (which we’ll discuss in the next article). The print function is one of the most frequently used parts of Perl. Almost all functions can be given a list of parameters, which are separated by commas. You can see a list of all the built-in functions on the perlfunc main page. They’re the verbs of Perl, the commands that the interpreter runs. The \n indicates the ``newline” character without it, Perl doesn’t skip to a new line of text on its own. From a command line, go to the directory with this file and type perl. (Traditionally, first programs are supposed to say Hello world!, but I’m an iconoclast.) Take the following text and put it into a file called : #!/usr/local/bin/perl It’s OK if you’re running Windows most Perl code is platform-independent. In this series, I’m going to assume that you’re using a Unix system and that your Perl interpreter is located at /usr/local/bin/perl. In this first part of our series, you’ll learn a few basics about Perl and see a small sample program. The Perl slogan is ``There’s more than one way to do it,” and that lends itself well to large and small problems alike. It plays well with your personal programming style. It also didn’t hurt that Perl is a friendly language. C is complex and can produce security problems (especially with untrusted data), Tcl can be awkward and Python didn’t really have a foothold. More importantly, Perl was appreciably better than the alternatives at the time when people needed something to use. Why did Perl become so popular when the Web came along? Two reasons: First, most of what is being done on the Web happens with text, and is best done with a language that’s designed for text processing. Since then, it has moved into a large number of roles: automating system administration, acting as glue between different computer systems and, of course, being one of the most popular languages for CGI programming on the Web. It was first developed by Larry Wall, a linguist working as a systems administrator for NASA in the late 1980s, as a way to make report processing easier. Perl is the Swiss Army chainsaw of scripting languages: powerful and adaptable. A Beginner’s Introduction to Perl Web Programmingįirst, a Little Sales Pitch Table of Contents.A Beginner’s Introduction to Regular Expressions with Perl 5.10.A Beginner’s Introduction to Files and Strings with Perl 5.10.You might be interested in the newer versions, available at: Originally contributed by Korjavin Ivan, and updated by 10 contributor(s).Editor’s note: this venerable series is undergoing updates. Got a suggestion? A correction, perhaps? Open an Issue on the Github Repo, or make a pull request yourself! Perlfaq contains questions and answers related to many common tasks, and often provides suggestions for good CPAN modules to use. # Scalars # A scalar represents a single value: my $animal = "camel" my $answer = 42 my $display = "You have $answer $ 1 # Object-oriented programming is covered more thoroughly in perlootut, # and its low-level implementation in Perl is covered in perlobj. # Perl has three main variable types: $scalar, and %hash. # A valid variable name starts with a letter or underscore, # followed by any number of letters, numbers, or underscores. # Perl variable types # Variables begin with a sigil, which is a symbol showing the type. Strict causes # compilation to fail in cases like misspelled variable names, and # warnings will print warning messages in case of common pitfalls like # concatenating to an undefined value. # Strict and warnings use strict use warnings # All perl scripts and modules should include these lines. # Single line comments start with a number sign.
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