Some people find programming boring, some find it fun. But every programmer must keep up with programming language trends. Most programmers start learning programming from C, because C is the most commonly used language for writing operating systems and applications.
C Programming Notes
These are some notes from the introductory C programming class at Washington Experimental College. They are modified based on the supplementary notes of "The C Programming Language" (started in the spring of 1995), and the authors of this book are the famous Brian Kernighan and Dennis Ritchie, people affectionately call them K&R.
Programming in C - UNIX system calls and subroutines
David Marshall's "Programming in C Tutorial" covers application design, UNIX system calls and subroutines.
Chris Sawtell's C Language Tutorials
These documents contain a complete course for you to learn the C language itself. The writing uses correct, traditional English. The author uses the same language structure, and if I were to teach you directly, I would use it the same way.
C language FAQ collection
Steve Summit maintains a collection of C language FAQs, which he also published in the book "Frequently Asked Questions in C Programming" (Addison-Wesley Publishers, 1995, ISBN 0-201 -84519-9).
Lysator Society's C language material collection
This is an electronic collection of C language materials on the Lysator Society website. Lysator is an academic computing community located at Linköping University in Sweden.
Some useful libraries written in C
This is a very useful classification of free software or libraries. These software generally run on free operating systems, especially the GNU operating system and its GNU/Linux branch. .
C language standard
ISO/IEC JTC1/SC22/WG14 is the international standardization organization for C language.
High-level and low-level of C language
You can use some tools and styles to extend C to give it some "high-level" language features. At the same time, you can also skip some very common features of C and use the underlying functions directly.
Microsoft's C Language Reference
This "C Language Reference" describes the C language used by Microsoft. The structure of the book is based on the ANSI C standard, and also adds Microsoft's extensions to the ANSI C standard.
Online C/C++ tutorials and documentation
This page contains links to free electronic documentation, instructions, tutorials, references, FAQs, C and C++ books, etc.