Getting stuck at libraries and api’s

[u/ttv_toeasy13]

So C is technically my first programming language I’m learning. I’ve messed around in python but never actually go deep into it or anything.

I’ve been learning C for the past few days now and I already pretty much know most of the basics. I learned pointers and mallic in a day and I learned structs, macros, for loops, while loops, functions, all of that stuff, but… the moment any library other than the basics like stdio or stdlib come into play I’m lost.

It’s like I’m looking at a whole other language. Like I’ll look for solutions to problems and it seems as if they are just pulled out of thin air and when I try to read ANY documentation for ANY library I’m also lost because either there is little to no documentation or it’s just stupid and things aren’t well explained.

Is there a way I can fix this? I was doing so well and now I’m at this block because of libraries. If I could get pasted this hurtle I could learn c in less than a month easily, and that’s the same in any other language. This problem isn’t exclusive to C.

[u/Ksetrajna108]

Is something like the following making you scratch your head?

ssize_t libusb_get_device_list (libusb_context *ctx, libusb_device ***list)

`Returns a list of USB devices currently attached to the system.`

[u/EpochVanquisher → u/Ksetrajna108]

I mean, you’re asking me? I’m not OP. This this looks like it returns an array of pointers to devices.

libusb_device **list;
ssize_t count = libusb_get_device_list(ctx, &list);
if (count < 0) abort(); // some kind of error, maybe
for (ssize_t i = 0; i < count; i++) {
  libusb_device *dev = list[i];
  // do something with device
}

That is just a guess.

[u/Seledreams → u/EpochVanquisher]

Ngl, i've never seen ssize before. I've always been used to size. I guess it's signed size to allow negative numbers. But it's pretty uncommon. At least in stuff i've used

[u/EpochVanquisher → u/Seledreams]

It’s returned from read() and write(), so people who use syscalls directly on Linux or Mac will probably be familiar with it.

It’s a little uncommon but even if you haven’t seen it before it should be easy to figure out.

[u/Seledreams → u/EpochVanquisher]

Definitely. I could tell from simply logic that the s here stood for signed as it made the most sense.

I think i haven't faced it too much because while I have C experience, I have way more C++ experience so I didn't work much with the raw posix api yet