What are CGI scripts used for these days?

Question

I'm pretty well up to speed on general web programming languages, but one of the tools I'm working with right now is in CGI. All I can tell is that CGI scripts are quite slow.

Is CGI still commonly used today? If not, what has it been replaced by?
Are there any niche functions in which CGI is still alive and actively used?

I have read the 2 answers so far and my question is: are there any niche functions which cause CGI to stay alive and used? — Smandoli, Jul 21 '09 at 22:14
Ok, I'll remove the accepted for now, that's an interesting point as well. — Dirk, Jul 21 '09 at 22:16
@SilentGhost -- you mean, it isn't a programming question? It seems like one to me. — Smandoli, Jul 21 '09 at 22:28
it doesn't look community wiki to me. It has a non-subjective answer. — Decio Lira, Aug 31 '09 at 19:45

score 34 · Answer 1 · answered Jul 23 '09 at 10:16

CGI is protocol, it is most basic and most standard way to create dynamic pages.

There are many cases where it is useful:

When you want to create, a basic application in a language without mod_XYZ, let's say C or Haskell, that may be computation intensive.
In embedded systems, where memory is expensive and you prefer to spawn a CGI script rather then holding it in memory all the time.
On some hosting services where you want to give flexibility to write server side software in any technology you want, but on the other hand do not hold president applications in memory using FastCGI (for example Sourceforge hosting).
The loads on CGIs are low so you don't care about spawning applications per request. For example, in blogs like MoveableType, only updates are done via CGI, all the rest is served via static pages, which CGI script changes when needed. So the cost of spawning CGI script is very low.
When most of your content is static pages and you want to serve it with server like thttpd, so very few operations that are done can be done via CGI that it supports.

So... CGI is simple but still very useful API, allowing to do stuff simply.

For example, the script that shows uptime of your server

#!/bin/bash
echo Content-Type: text/plain
echo
uptime

What can be simpler, easier and less web-server dependent?

aem · Accepted Answer · 2009-07-21T22:19:57.193

20

CGI has been replaced by a vast variety of web programming technologies, including PHP, various Apache extensions like mod_perl, Java of various flavors and frameworks including Java EE, Struts, Spring, etc, Python-based frameworks like Django, Ruby on Rails and many other Ruby frameworks, and various Microsoft technologies.

I'm sure CGI is still used for something, but I'd guess it's mostly just little bits of code that have been sitting around for years. Wikipedia does helpfully mention that FastCGI is similar to CGI but without the massive performance drawbacks.

edited Jul 21 '09 at 22:19

answered Jul 21 '09 at 22:12

aem

3,896
24
20

1

Well I use CGI in embedded world, with executable files being called thru the CGI gateway, and it performs much better than PHP or Java because the pages behind the scened are actually compiled executables written in C. However, writing web pages in PHP or Java is much fast and easier than doing it in C. – Claudi Mar 07 '13 at 07:05

score 5 · Answer 3 · answered Jul 21 '09 at 22:18

5

Many legacy websites are still built with cgi today, although people these days are moving away from it. One of the well renown application that is still using CGI that I know is MovableType blog.

answered Jul 21 '09 at 22:18

Joshua Partogi

16,167
14
53
75

score 2 · Answer 4 · answered Jul 22 '09 at 00:31

I know of 2 projects that are being actively being developed that still use CGI scripts to good effect.

The first is Webmin a web-based system administration tool that I've been using for years.

The second is GitWeb which allows you to setup a web interface to your Git repositories.

As to the speed of CGI (or lack thereof) I can't really comment on that. From my experience with Webmin I can't say I've had any issues on that front.

score 2 · Answer 5 · answered Aug 31 '09 at 19:34

2

Real time operating systems where porting (for example, PHP) is not an option.

answered Aug 31 '09 at 19:34

T.T.T.

33,367
47
130
168

score 1 · Answer 6 · answered Jul 22 '09 at 00:44

1

Many shared hosts serve server side languages like PHP, python and perl through CGI

answered Jul 22 '09 at 00:44

blockhead

9,655
3
43
69

score 1 · Answer 7 · answered Dec 05 '12 at 12:53

1

I still use it on embedded computers which do not have php Language support.

answered Dec 05 '12 at 12:53

Vincenzo

1,549
1
9
17

score 0 · Answer 8 · answered Jul 21 '09 at 22:11

0

ASP, PHP, ASP.Net, Ruby on Rails are the big hitters these days.

answered Jul 21 '09 at 22:11

Spencer Ruport

34,865
12
85
147

score 0 · Answer 9 · answered Jul 21 '09 at 22:17

0

Much like Cobol and Fortran there are some big money systems built on CGI that will of course be maintained well into the future.

Not that newer software isn't built with all those technologies from time to time.

answered Jul 21 '09 at 22:17

Matthew Vines

27,253
7
76
97

score 0 · Answer 10 · answered Jul 21 '09 at 22:23

A project I left a few months ago still uses CGI. However, the site is for a very small user set (it only has about 40 users, and probably less than 5 use it frequently). While the hardware has been replaced 3 or 4 times, some of that code has been running for almost 10 years, with little or no modification. I'm sure other technologies would provide a performance improvement, but current performance is acceptable, and manpower to make a change is short, spread over too many areas, and not well versed in web technologies (especially since I left). This leads to an attitude of "If it ain't broke, don't fix it!"

As for replacements I've used/plan to investigate: In my new position, I've developed a web app with PHP. However, I'm more of a Python fan and plan to look into WSGI soon. I also plan to use AJAX to replace a CGI program on a site I voluntarily maintain for a non-profit.

How will AJAX *replace* a CGI program? AJAX isn't a server-side technology in itself, it's simply a technique for running server-side scripts without a full page load. — DisgruntledGoat, Jul 22 '09 at 00:39
@DisgruntledGoat: Currently the page displays a table with data from a back end database and a form below the table. When a user submits data via the form a CGI program processes and updates one cell in the table. I've not really done any AJAX yet, so maybe I'm off base, but my plan is to make the table into a form, eliminating the separate form, and use AJAX to process the user's entries and directly update the database. — PTBNL, Jul 22 '09 at 01:53

Dave Burton · Answer 11 · 2022-02-12T17:28:22.973

CGI and newer technologies are not mutually exclusive. They can be complementary.

My Extreme Precision Binomial Probability Calculator (written in 2020 - 2021) is implemented using both PHP and CGI Perl, working together along with GMP, and a tiny bit of JavaScript.

Perl's support for arbitrary precision arithmetic, and its interface to the GNU Multiple Precision Arithmetic Library (GMP), make it a good language for implementing a tool like this. The same code runs both as a Perl command-line tool and as a CGI module. (In fact, on my server the download link for the binomcalc.pl command-line tool is actually just a Linux symlink to the binomcalc.cgi module.)

PHP (and HTML, CSS & JavaScript) are better for creating the Web interface.

The PHP code generates a CGI include directive, passing parameters to the Perl code. The Perl & GMP code then do the calculations, and generate the results, which appear on the web page.

What are CGI scripts used for these days?

11 Answers11

Linked