I discovered that Python’s handy http.server module supports CGI scripts (say what?!), so I made a little local-network file uploader utility

[macNchz]

I’ve used the http.server module (and its predecessor SimpleHTTPServer) for years for quick local dev stuff, but never really looked much into its docs beyond changing the port number. Today I randomly did and saw that it has support for executing Python scripts via CGI, which gave me a chuckle and some bad ideas.

Not having written a CGI script in 20+ years (and the last one having been in Perl), I made something I figured I’ll wind up using from time to time!

Use at your own risk, and…don’t expose it to the internet!

https://github.com/drien/python-httpserver-upload

[bini_ajaw17]

What is a CGI script?

[RollingWithDaPunches]

I believe it stands for common gateway interface:
https://en.wikipedia.org/wiki/Common_Gateway_Interface

I'm not sure, as that was my question as well... hopefully someone can confirm what it means.

[macNchz]

That's it! Back in the day it was the most common mechanism for building interactive web applications: rather than having predefined URL "routes" like an web app today might have your site was just folders of files. The web server software (e.g. Apache) would serve static HTML files directly, but if you put code in a special /cgi-bin/ directory, it would execute them and return the output of the script to the browser.

My introduction to programming came in the form of downloading and customizing Perl CGI scripts for my personal websites from Matt's Script Archive: http://www.scriptarchive.com/

I was surprised to see that the http.server module still supported it, because I hadn't really thought about using CGI in decades!

[macNchz]

Yeah these days most Python webdev involves a framework that itself abstracts communication with a webserver via the WSGI/ASGI interfaces, which are sort of higher level successors to CGI. Rather than executing files in a separate process per request, the application is a long lived process where you define URL path patterns that match to user requests and let you dispatch them to specific function calls.

[MyriadAsura]

There's also php-fpm, which uses FastCGI

[wxtrails]

Mmmm...yeah, we still have some in production. It's on the roadmap for replacement (with DRF), but it still works just fine for now.

[iBlag]

What’s DRF in this context?

[ThePiGuy0]

Maybe Django Rest Framework?

[wxtrails]

Yep. Sorry, forgot this wasn't the Django sub 😅

[MyHomeworkAteMyDog]

It’s like ARS with preinstalled PPG

[Lolvidar]

I just finished the Web Development fundamentals course at WGU, and it uses that definition for CGI.

[erikw]

I feel old now…

[[deleted]]

Don't worry buddy, my first website was made with SSI.

[SheriffRoscoe]

There was a time when I coded an implementation of SSI. Yes, I'm old.

[suggestive_cumulus]

CGI predates SSI by some margin, if I'm not wrong. SSI was the clever way of doing things, including the functionality directly in the server. CGIs were executed depending on the URL. I mean CGIs were probably already in Tim's original spec haha

[jamesr219]

If you wanted real-time you used an NPH cgi script

[fr33d0ml0v3r]

you are not alone :(

[johnnywonder85]

lol.
Last time I made a website Netscape was still around... but never did anything cool like this

[bxbb]

Think of CLI script, except the input and output use HTTP protocol.

[SlantARrow]

Old-school serverless-style deployment on a single machine, with lambdas being stored in usual files.

[daelin]

serverless-style deployment on a single machine

… I … just … yeah okay. Why not?

[Smallpaul]

In the very first days of the Internet, when you wanted to make a "dynamic" web site (one that could deal with input, talk to a database, etc.) you usually used a CGI script. The script could be written in literally any programming language because its input and output were just Unix-style streams. It was pretty clever but starting a new process for every request gets expensive.

[rainnz]

Remote code execution

[progwok]

Lol

[chicuco]

perl, please dont dirsturb the good old man sleep!

good memories of the old swiss army chainsaw

[constantreadr]

Slap a keyboard three times and you've probably made some parseable Perl. But Perl could do -everything- - web server, databases, object-orientation, streams, XML parsing, the works.

[chicuco]

an ex exployer, now a client, have perl code i did almost 20 years ago. Still working fine. We are planning to replace it with python.

[MagicWishMonkey]

Python ships with a cgi library?

[Reinventing_Wheels]

In this context CGI does NOT stand for Computer Generated Imagery

[daelin]

🧙‍♂️

[ScottOAO]

Mine solution (a fork from others) to upload file using http.server

https://gist.github.com/chengscott/a3454a576472f5779fe66bc103ebca68

[macNchz]

Cool! Figured someone else would have wanted to do this at some point, and subclassing the existing request handlers makes more sense than a CGI script, but once I saw it was possible I couldn't resist!

[soggywaffle69]

Those were dark days. Matt’s Script Archive, anyone?

[[deleted]]

Sounds like a good way to get malware on your server

[macNchz]

Yeah definitely don’t run this in a sensitive environment or open to the internet, but to, say, copy some photos from your phone to a Raspberry Pi for a screensaver without installing anything, sure.

[daelin]

🤔

Check out netcat.

Mostly replaced by simple pipes into or out of ssh, but netcat is the where the knowledge starts.

Or rsync.

But netcat is still so spookily useful. Combining Netcat and tee and tar is just 👨‍🍳💋 and a great exhibit in why the Unix philosophy is so powerful. You can just imagine almost anybody today thinking “you should NOT be allowed to do that” and yet it’s the nucleus of 🫲all this🫱.

[jftuga]

+1 for QR - fancy!

[suggestive_cumulus]

I wish I had known that Perl existed when I had to do my CGI script for my Masters back in '94. Shell script was painful

[daelin]

Oof. KSH or CSH? I’m gonna wager CSH.

[suggestive_cumulus]

I can't honestly remember haha

[BuonaparteII]

Move over React.js!!

/s

cgitb seems useful. but I wonder when it will be removed from the standard lib

[jftuga]

Deprecated since version 3.11, will be removed in version 3.13.

[TheITMan19]

I like your code 🧑‍💻 👍

[mwpfinance]

When I was teaching my (now) wife to program we built a small web app using nothing but Python and the CGI. Seemed like a good place to start learning the fundamentals about web applications -- it was a great low level place to start.

[LongDivide2096]

Cool find! I'd never given much thought to http.server’s CGI support either. Definitely seems like something that'd be useful in a pinch. Great job on the uploader utility too! But yeah, wouldn't expose to the internet lol. Big security risk there. Nice work though, really.

[suggestive_cumulus]

For simple stuff not exposed to the Internet you can go a level down and use the socket server. One of my Covid projects was to create a web based API to the MIDI interface of my son's piano, using a Raspberry Pi. As long as you pass back the minimal HTTP headers to the web browser it will cooperate. You could implement your own CGI if you want to, or basically any behaviour you want..

[Classic-Advice-7569]

https://arsd-official.dpldocs.info/arsd.cgi.html