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As a web developer, 90% of what you just wrote is nonsense to me. How did you learn this stuff? Do you use it for useful projects or just for fun?

matheusmoreira 2y ago
Curiosity and free time. You learn stuff like this by reading tens of thousands of lines of text and code for every line of code that you write. I've always been all about the hidden fun stuff. The magical little programs that somehow configure audio cards. The ALSA mixer tool for example does it via special ioctls. I was reading its source code not too long ago. The manuals said those definitions were for the curious and that those ioctls were private, as though it was the library's author exclusive privilege to use those things. I seriously hate it when they say that. When they imply I'm some mere mortal who's better off using the libraries that were gifted to us by the gods of programming. Good or bad, quite a bit of hubris is involved. Takes a certain audacity to think I can make a better wheel than people who are probably much smarter than I am. Sometimes I start projects just to prove to myself that I'm not clinically insane for thinking a better way is possible. Sometimes it works, sometimes it doesn't. Someone once called an idea I had schizophrenic. I'll never forget that day. This Linux system call stuff started after I read an LWN article about glibc and Linux specific system call support, getrandom to be specific. Took glibc years to add support. I started a liblinux project because of that article. The idea was to get rid of libc and talk to Linux directly. In order to accomplish that, I was forced to learn a lot of compiler, linker and executable stuff. The musl libc source code taught me a lot. It seems like the C library is doing a huge amount of stuff but it turns out you don't actually need most of it. Linux just puts your binary in memory and jumps into some address specified in the ELF header. Normally this when the C library or dynamic linker takes over in order to prepare to call main(). Turns out I can just replace all that with some simple code that calls a function and then exits the process when it returns. It just works. I won't have init/fini section processing but I can live with that, that's harmful stuff that shouldn't even have been invented to begin with.

matheusmoreira 2y ago

Curiosity and free time. You learn stuff like this by reading tens of thousands of lines of text and code for every line of code that you write. I've always been all about the hidden fun stuff. The magical little programs that somehow configure audio cards. The ALSA mixer tool for example does it via special ioctls. I was reading its source code not too long ago. The manuals said those definitions were for the curious and that those ioctls were private, as though it was the library's author exclusive privilege to use those things. I seriously hate it when they say that. When they imply I'm some mere mortal who's better off using the libraries that were gifted to us by the gods of programming. Good or bad, quite a bit of hubris is involved. Takes a certain audacity to think I can make a better wheel than people who are probably much smarter than I am. Sometimes I start projects just to prove to myself that I'm not clinically insane for thinking a better way is possible. Sometimes it works, sometimes it doesn't. Someone once called an idea I had schizophrenic. I'll never forget that day. This Linux system call stuff started after I read an LWN article about glibc and Linux specific system call support, getrandom to be specific. Took glibc years to add support. I started a liblinux project because of that article. The idea was to get rid of libc and talk to Linux directly. In order to accomplish that, I was forced to learn a lot of compiler, linker and executable stuff. The musl libc source code taught me a lot. It seems like the C library is doing a huge amount of stuff but it turns out you don't actually need most of it. Linux just puts your binary in memory and jumps into some address specified in the ELF header. Normally this when the C library or dynamic linker takes over in order to prepare to call main(). Turns out I can just replace all that with some simple code that calls a function and then exits the process when it returns. It just works. I won't have init/fini section processing but I can live with that, that's harmful stuff that shouldn't even have been invented to begin with.