C Programming

cprog

The C programming language is at the heart of GNU/Linux - it is the programming language most of the Linux Kernel and GNU tools is written in.

There are many outstanding books and online resources where you can learn C and as such this site will not try and duplicate these efforts.

What I will try to do here is try to complement other sources, trying to explain parts which are easily overlooked by beginners or are difficult to remember. I hope that you like what is on offer and if you do, please bookmark these pages and spread the word.

The C Language
- The Compiler
- Identifiers
- Literals
- Sorting the confusion between Storage Classes and Linkage
- C Operators
- C Syntax Structures
- GBD Debugger

Standard Library

The Standard Headers

stdarg.h - variadic functions

Macros:
va_start             enables access to variadic function arguments (function macro)
va_arg               accesses the next variadic function argument(function macro)
va_copy              (C99) makes a copy of the variadic function arguments (function macro)
va_end               ends traversal of the variadic function arguments (function macro)
Type:
va_list              holds the information needed by va_start, va_arg, va_end, and va_copy (typedef)
#include <stdio.h>
#include <stdarg.h>
void simple_printf(const char* fmt, ...)
{
    va_list args;
    va_start(args, fmt);
    while (*fmt != '\0') {
        if (*fmt == 'd') {
            int i = va_arg(args, int);
            printf("%d\n", i);
        } else if (*fmt == 'c') {
            // A 'char' variable will be promoted to 'int'
            // A character literal in C is already 'int' by itself
            int c = va_arg(args, int);
            printf("%c\n", c);
        } else if (*fmt == 'f') {
            double d = va_arg(args, double);
            printf("%f\n", d);
        }
        ++fmt;
    }
    va_end(args);
    }

Functions at a Glance Basic Tools

Compiling with GCC
Using make to Build C Programs
Debugging C Programs with GDB
Using an IDE with C
Unicode in C Problem Solving
StackOverflow: how-to-check-if-an-initialised-struct-is-empty-or-not
TutorialsPoint: c_type_casting

Videos

- [Learning C by VertoStudio3D](https://www.youtube.com/watch?v=JPAyj85tJ5E&list=PLT6WFYYZE6uLMcPGS3qfpYm7T_gViYMMt)
- [Intro to C by Molly Rocket Playlist](https://www.youtube.com/watch?v=F3ntGDm6hOs&list=PLEMXAbCVnmY6RverunClc_DMLNDd3ASRp)

Books

- [The-C-Programming-Language-2nd-Edition Source Code on Github](https://github.com/Heatwave/The-C-Programming-Language-2nd-Edition)
- [Build Your Own Lisp in C](https://www.buildyourownlisp.com/)
- [Dive Into Systems](https://diveintosystems.org/book/index.html)

Other External Links

- [devdocs.io](https://devdocs.io)
- [cppreference](https://en.cppreference.com/w/c)
- [Excellent Free Tutorials to Learn C - LinuxLinks](https://www.linuxlinks.com/excellent-free-tutorials-learn-c/)
- [richard-stallman-c-reference](https://www.i-programmer.info/news/184-cc/15705-richard-stallman-announces-c-reference.html)
- [Programming Simplified: C programming Examples](https://www.programmingsimplified.com)
- [Thee Geek Stuff: Variadic Functions](http://www.thegeekstuff.com/2017/05/c-variadic-functions/)
- [Wikibooks: Programming Termios](https://en.wikibooks.org/wiki/Serial_Programming/termios)
- [CHL - Create a Webapps in C](https://github.com/it4e/CHL/wiki/Tutorial)
- [libc manual](https://www.gnu.org/software/libc/manual/html_mono/libc.html#File-Positioning)
- [c-programming-projects-with-source-code-coding-projects-ideas](https://www.cselectricalandelectronics.com/c-programming-projects-with-source-code-coding-projects-ideas)