What are the important notions in C that you did not learn from your teachers? [closed]

Answer 1

Know that when you increment a pointer, the new address depends upon the size of the data pointed to by that pointer... (IE, what's the difference between a char* being incremented and an unsigned long*)...

Knowing exactly what a segmentation fault really is first of all, and also how to deal with them.

Knowing how to use GDB is great. Knowing how to use valgrind is great.

Develop a C programming style... For example, I tend to write fairly object oriented code when I write large C programs (usually, all the functions in a particular .C file accept some (1) particular struct* and operate on it... I tend to have foo* foo_create() and foo_destroy(foo*) ctor's and dtors...)...

Answer 2

The debugger is your friend. C is an easy language to mess up and the best way to understand your mistakes is often to see them under a debugger.

Answer 3

• Trashed memory can trigger all sorts of weird bugs.
• Debuggers can lie to you.

Answer 4

Hope this wasn't posted before (just read through very quickly), but I think what is very important when you have to work with C, is to know about the machine representation of data. For example: IEEE 754 floating point numbers, big vs little endian, alignment of structs (here: Windows vs Linux)... To practice this, it is very useful to make some bit-puzzles (solving some problems without using a any functionality then printf to print the result, a limited number of variables and some logical operators). Also it is often useful to have a basic knowledge about how a linker works, how the whole compiling process works etc.. But especially understanding the linker (without that, it is so hard to find some kind of errors...)

The book which helped me most to improve my C and C++ skills was: http://www.amazon.com/Computer-Systems-Programmers-Randal-Bryant/dp/013034074X

I think that a deep knowledge about computer architecture makes the difference between a good and a bad C programmer (or at least it is a significant factor).

Answer 5

Indent Style. All teachers were saying that code must be indented but noone really gave directions on how to indent. I remember all students' code was really a mess.

Answer 6

unsigned vs signed.

Bit shift operators

Bit masking

Bit setting

integer sizes (8-bit, 16-bit, 32-bit)