Perl
Perl stands for Practical Extraction and Report Language, which was created by Larry Wall. It is an interpreted programming language used for CGI. CGI stands for Common Gateway Interface. CGI can be used to create programs to update your web page. It also lets users send you e-mail and lets you check errors.
Perl is a jack-of-all-trades language. It is used for scripting (it can replace Unix Shell scripts), pattern-matching , list processing, and for systems functions. It is similar to C.
The Perl home page is at http://www.perl.com/perl. You can download Perl for free from http://www.perl.com/CPAN, where CPAN stands for Comprehensive Perl archive network. Perl will run through MS-DOS.The basic Perl syntax is:
Perl [options] [source_file | cmd]
The options include:
| Option | Description | Example |
|---|---|---|
-c | Check the syntax without running the program | $ perl -c firstprog |
-e | Single Perl command from command prompt. | $ perl -e 'print("Hi!\n")' |
-v | Print the version number (no program needed). | $ perl -v |
-w | Print warnings. | $ perl -w firstprog |
Statements should be terminated with a semicolon. Statements can span multiple lines.
Variables and keywords are case-sensitive.
Curley braces, {}, are used around statement blocks.
Function parameter blocks may optionally be enclosed in parentheses ().
There are hundreds of Perl commands. They include:
Example - tracking where your hits come from
Perl Control Constructs (loops, branches)