Mod perl
Encyclopedia
mod_perl is an optional module for the Apache HTTP server
. It embeds a Perl
interpreter
into the Apache server, so that dynamic content produced by Perl scripts
can be served in response to incoming requests, without the significant overhead of re-launching the Perl interpreter for each request. As Lincoln Stein
defined mod_perl in his words:
mod_perl can emulate a Common Gateway Interface
(CGI) environment, so that existing Perl CGI scripts can benefit from the performance boost without having to be re-written.
Unlike CGI (and most other web application environments), mod_perl provides complete access to the Apache API
, allowing programmer
s to write handlers for all phases in the Apache request cycle, manipulate Apache's internal tables and state mechanisms, share data between Apache processes
or thread
s, alter or extend the Apache configuration file
parser
, and add Perl code to the configuration file itself, among other things.
Apache HTTP Server
The Apache HTTP Server, commonly referred to as Apache , is web server software notable for playing a key role in the initial growth of the World Wide Web. In 2009 it became the first web server software to surpass the 100 million website milestone...
. It embeds a Perl
Perl
Perl is a high-level, general-purpose, interpreted, dynamic programming language. Perl was originally developed by Larry Wall in 1987 as a general-purpose Unix scripting language to make report processing easier. Since then, it has undergone many changes and revisions and become widely popular...
interpreter
Interpreter (computing)
In computer science, an interpreter normally means a computer program that executes, i.e. performs, instructions written in a programming language...
into the Apache server, so that dynamic content produced by Perl scripts
Scripting language
A scripting language, script language, or extension language is a programming language that allows control of one or more applications. "Scripts" are distinct from the core code of the application, as they are usually written in a different language and are often created or at least modified by the...
can be served in response to incoming requests, without the significant overhead of re-launching the Perl interpreter for each request. As Lincoln Stein
Lincoln Stein
Professor Lincoln D. Stein is a scientist and leader in bioinformatics and computational biology at the Ontario Institute for Cancer Research. Current projects include Reactome, WormBase,, BioPerl, , ENCODE , the Generic Model Organism Database and Cloud computing...
defined mod_perl in his words:
mod_perl can emulate a Common Gateway Interface
Common Gateway Interface
The Common Gateway Interface is a standard method for web servers software to delegate the generation of web pages to executable files...
(CGI) environment, so that existing Perl CGI scripts can benefit from the performance boost without having to be re-written.
Unlike CGI (and most other web application environments), mod_perl provides complete access to the Apache API
Application programming interface
An application programming interface is a source code based specification intended to be used as an interface by software components to communicate with each other...
, allowing programmer
Programmer
A programmer, computer programmer or coder is someone who writes computer software. The term computer programmer can refer to a specialist in one area of computer programming or to a generalist who writes code for many kinds of software. One who practices or professes a formal approach to...
s to write handlers for all phases in the Apache request cycle, manipulate Apache's internal tables and state mechanisms, share data between Apache processes
Process (computing)
In computing, a process is an instance of a computer program that is being executed. It contains the program code and its current activity. Depending on the operating system , a process may be made up of multiple threads of execution that execute instructions concurrently.A computer program is a...
or thread
Thread (computer science)
In computer science, a thread of execution is the smallest unit of processing that can be scheduled by an operating system. The implementation of threads and processes differs from one operating system to another, but in most cases, a thread is contained inside a process...
s, alter or extend the Apache configuration file
Configuration file
In computing, configuration files, or config files configure the initial settings for some computer programs. They are used for user applications, server processes and operating system settings. The files are often written in ASCII and line-oriented, with lines terminated by a newline or carriage...
parser
Parsing
In computer science and linguistics, parsing, or, more formally, syntactic analysis, is the process of analyzing a text, made of a sequence of tokens , to determine its grammatical structure with respect to a given formal grammar...
, and add Perl code to the configuration file itself, among other things.