Published: Friday, February 11, 2000
Using PerlScript to Create ASP Pages
What is Perl?
Perl is an interesting scripting language that attempts to bring together everything cool from all other
languages (according to Larry Wall, the author of Perl).
Perl has a religious-like following in the world of UNIX systems administrators, and is used for a wide
variety of tasks. With the explosion of the World Wide Web, it was discovered that Perl could easily be used
as a dynamic scripting side language for Web sites, and many dynamic Web sites running on UNIX platforms
employ the use of many Perl scripts. If you ever visit a page with a .pl extension, chances are
it is a Perl script.
I find Perl to be a fun language to program in, but it is not nearly as English-like as VBScript. Perl
intrinsically supports three main data types: scalars, arrays, and associative arrays (hashes/Dictionaries).
With these intrinsic datatypes, along with intrinsic file handling and regular expression capabilities,
make Perl a very "useful" language, espcially for file processing. Perl has its roots in a myriad of languages
like C, Fortran, awk, and sed, so its syntax is very far from VBScript. However, I think Perl is a language
worth learning. If you already know C/Fortran or Java/JavaScript well, you will pick up Perl rather quickly.
To learn more about Perl, be sure to visit Perl.com.
OK, so What is PerlScript?
PerlScript is an ActiveX Scripting Engine put out by the good folks at
ActiveState. From the ActivePerl
Web site on ActiveState.com, you can download ActivePerl, which contains Perl for Win32, Perl for ISAPI, and,
most importantly, PerlScript.
When using an ASP page, you can tie into any compliant ActiveX Scripting Engine. The one most commonly used
is the VBScript ActiveX Scripting Engine. However, there is nothing to prevent you from using another server-side
scripting language like PerlScript. Once you've downloaded
and installed ActivePerl on your Web server, you can begin to use PerlScript in your ASP pages (note that you can
also use PerlScript in your WSH scripts as well)! To do so,
you need to include the following line of code on your ASP pages that you wish to use PerlScript:
<% @LANGUAGE="PerlScript" %>
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Now, start writing PerlScript code! As with JScript, PerlScript is case sensitive. Furthermore, PerlScript uses
a prefix character to indicate the type of variable being used. For example, if you wanted to create a scalar
variable, you need to prefix it with a $. (Scalar variables are variables that are not arrays or
associative arrays. An example of a scalar would be a string, and integer, or whatnot.) To declare variables,
use the keyword my in place of the Dim keyword in VBScript.
The ASP intrinsic objects are accessed by prefixing the object name with a $. For example, to
output, "Hello, world!", you could do:
<% @LANGUAGE="PerlScript" %>
<%
$Response->Write("Hello, world!");
%>
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Each statement needs to end with a semicolon (similar to JScript). Note that rather than using a period to
access a method of an object (as in Response.Write), an arrow is used (->). A
slightly more involved ASP page follows:
<% @LANGUAGE="PerlScript" %>
<%
# Note that a pound sign denotes a comment
my $name;
$name = "Scott";
$Response->Write("Hello, $name!");
%>
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Note that when using PerlScript, you simply place the variable name in the string. PerlScript will seach the
output string for words prefixed by a $ and displays those as variables.
Now, this article wasn't intended as a tutorial for PerlScript. Rather, its intention was to inform you about
the ability of using PerlScript as an alternative server-side scripting language.
Happy Programming!
