How to write your own code libraries in C.

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Welcome! I post videos that help you learn to program and become a more confident software developer. I cover beginner-to-advanced systems topics ranging from network programming, threads, processes, operating systems, embedded systems and others. My goal is to help you get under-the-hood and better understand how computers work and how you can use them to become stronger students and more capable professional developers.

About me: I'm a computer scientist, electrical engineer, researcher, and teacher. I specialize in embedded systems, mobile computing, sensor networks, and the Internet of Things. I teach systems and networking courses at Clemson University, where I also lead the PERSIST research lab.

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You can also find more info about code reviews here.

[mr]

this video saved an intern who's new to the cross compilation world.

[boxedowl]

Kids these days have it so easy. 20+ years ago if you lived in the middle of nowhere you'd be lucky to find a compiler on floppies, then never find compatible books. It took software piracy and haggling with an alcoholic college dropout living in a camper to score a copy of Borland Turbo C v2.04 AND a highly used copy of Waite Group's Turbo C Programming for the PC by Robert Lafore... That book never stopped smelling like a tool shed.

Your short C vids are fantastic! Especially ones on more complex topics.

[karlforshaw]

This is brilliant, thank you. Would be a nice intro to a larger video on dynamic code loading at runtime.

[danieleccleston]

4:13Thank you, this is something that I don't think is explained in many tutorials for setting up dynamic link libraries and was very confusing for me.

[prospermatkovic]

Excellent videos on the channel, and this one is no different. I think of them as similar to the process of making a fine espresso coffee. A lot of knowledge is condensed into well structured, rich and concise information. But not just that, well produced and even entertaining. This is the gold standard of howto programming videos

[ammartirmizi]

I literally had to pause the video to comment. Thank you Sir Jacob for educating the masses with such sheer brilliance!

[arthur_p_dent]

Dude 🙏 this has been so informative, can express enough how grateful I am. Not only have I learned a bunch about creating libraries, I also learned a bit more about using makefiles. I use gcc and was relieved that I didn’t have to change anything.

Again, much thanks.

[thezeegamingc]

Note that in your header your include guard starts with two underscores, and I believe that violates the C standard as those are reserved

[jeremiahyonemura]

A lot of that information went right over my head. That was very fast for an AP CSP student, who just started using C in August.

[michaelkotthaus]

Thank you very much for these great tutorials! Very useful and good explained.
I have one annotation to your code: The identifier __MY_CODE_H__ of your "include guard" may clash with identifiers of the compiler implementation. (For this identifier it is unlikely.) The C standards specify that certain identifiers are reserverd for the implementation, particularly those with two underscores. So, you may better want to use just MY_CODE_H for this purpose.

[vb]

Me: Tons of information in 10 minutes?
Jocob: YES! Damn it..

[benjaminshinar]

three months ago, this video would have saved me some hours!

can you do a video about dynamically linked libraries?

[tothespace]

4:08 Why is "-l<name>" needed during build time? Doesn't that beat the whole purpose of shared libraries? Why not just use static libraries if both need to be present at build time. I would expect to be able to build my main program without specifying ANYTHING about the shared library, otherwise it's not really dynamic.

[bettyswunghole]

Thank you for this vid! I immediately spotted what I was doing wrong (not #including my header file in my library source file).

[koobe]

I was calling my library header.a, and I wasted hours trying to make the linker find it, that was until you mentioned the lib- as (libheader) detail, thanks!

[edgar]

Heyyy, you should try to make a video on how to make your own data structures or the thought process behind it. That would be super cool

[sudarshanv]

in windows cmd, type "set _env_name = "_path_" "for setting temperorarily setting environment variable.
for permanent setting use "setx" instead of "set"

[sghsghdk]

The searchpath for the runtime liker can be mangled during compilation as well.

You basically have to link your executable like this (untested):

gcc -o bin *.o -Wl, --rpath="$ORIGIN"

This will make the runtime linker look in the same directory as the executable (this behavior is as far as I remember default on windows).

[jesvinjohnson]

Your videos are awsome. straight to the point.

[coolbrotherf]

Very helpful. I knew how to do this stuff with Visual Studio on Windows, but there wasn't a whole lot of stuff about how to do this stuff in Linux.