Logo for the kthoom comic book reader

I use my open source comic book reader, kthoom, quite a bit (more than I probably should!). Every once in awhile, I’ll come across a comic book file that kthoom won’t open and I’ll delightedly set some time aside in the evening/weekend to work on fixing the JavaScript. Hacking keeps me sane.

This year, I uncovered several CBR files that use a little-known feature in the RAR format for a VM (virtual machine). If it sounds ridiculous that an archive format has support for a VM, you’re not alone – and I think it was removed in later versions of the RAR archiver (someone correct me if I’m wrong!).

Clipart image of a zipper

Anyway I’ve been steadily building support for the various filters in RarVM into my Binary Tools for JavaScript open source library. Perhaps the smarter thing to do would be to use asm.js or WebAssembly and some tools to convert the C/C++ unrar project into JavaScript, but I’m having fun reverse-engineering the code and improving the documentation / understanding while porting it to a new language, so leave me alone! 😛

In terms of Comic Book Archive files, kthoom supports CBZ, CBR and CBT files. I’ve never encountered a CB7 / CBA file – but it might be a fun and ambitious project to add support for 7zip and Ace compression formats to bitjs.archive… hint hint 😀

§1115 · November 1, 2017 · Comic Books, Open Source, Software, Technology, Web · · [Print]

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