Several years ago, I wanted to setup a personal wiki on my raspberry pi. However, the distribution I used back then did not have a PHP package for ARM. So instead of switching distributions or searching for other wikis that I could use, I simply decided I would write one in C. Yes, that's an odd way to approach the problem and indeed, I may have had too much time back then. Also, I wanted to see how it's like to write a "web app" in C and wanted to sharpen my C skills a little bit.

Of course, it's pretty straightforward at first. No really: Just use CGI and print your HTML to stdout.And indeed, that would have been more than enough for my use cases.

But then I decided to play around and started using FastCGI (with the official library from now defunct fastcgi.com) and created a multi-threaded version. It initially used a "pile of files database", but that became too painful, so then I started using sqlite.

C++

Eventually, since it was mostly a playground for me, the code became unmaintainable. Furthermore, I initially wanted something quick and given that it was CGI, I didn't bother taking care of memory leaks. After initiating a FastCGI interface, they became an issue and then the task of avoiding memory leaks became too annoying. And of course, C does n ot include any "batteries" and while I could manage, this too was another good reason.

Overall, I am just continuing the experiment with >=C++17 now. It's not nearly as bad as you would expect perhaps. Some things are surprisingly convenient even. Still, the standard library is lacking and I would hope for a some better built-in Unicode support in future C++ standards.

Features

Some essential features are lacking, such as a diff between revisions, user registration UI, etc.

It doesn't compete with any other software anyway.

CGI
HTTP server using the header only library cpp-httplib. It's more portable and more "future-proof" than FastCGI (since the official website disappeared, the library's future appears to be uncertain).
Support for user accounts. Passwords are stored using PBKDF2. sqlite database, but not too much of an effort to add other types of storage backends. sqlite is using the great header only library sqlite_modern_cpp
Relatively fine-grained permission system.
Categories
Templates
FTS search
Caching
Blog-like functionality
RSS/Atom feeds

Security

exile.h is used to restrict access to the files the wiki needs. It doesn't have access to other paths in the system and the system calls that the qswiki process can make are restricted.

As for "web security", all POST requests are centrally protected against CSRF attacks and all input is escaped against XSS attacks.

Building

Dependencies:

cpp-httplib: https://github.com/yhirose/cpp-httplib
SqliteModernCpp: https://github.com/SqliteModernCpp
exile.h: https://gitea.quitesimple.org/crtxcr/exile.h
sqlite3: https://sqlite.org/index.html

The first three are header-only libraries that are included as a git submodule. The others must be installed, e. g. by using your distributions standard method.

If all dependencies are available, run:

  git submodule init
  git submodule update
  make release

Setup

To be written

Languages

C++ 97.7%

CSS 1%

Makefile 1%

Shell 0.2%

Dockerfile 0.1%