phase-1-language-core

Phase 1 - Fix the Foundation

Goals

Understand the C language properly. Stop guessing while coding. Clear up the confusion about stdin / stdout / buffers.

01-compilation-model

• Preprocessing
• Compilation
• Linking
• .h vs .c
• static vs extern

Nothing here yet. A good first exercise is to take one of the .c / .h pairs in 03-pointers and run it through gcc -E, gcc -S, gcc -c and the linker by hand, looking at the output of each stage.

02-types-and-memory

• Integer sizes
• Signed vs unsigned
• char as a number
• Endianness

Nothing here yet. Write a program that prints sizeof for every integer type, and one that detects the machine's endianness by casting an int* to a char*.

03-pointers

• Pointer basics
• Pointer arithmetic
• Pointers to arrays
• Pointers to structs
• Double pointers
• Function pointers

swap-ints.c, swap-strings.c, double-pointer-allocate.c and array-of-struct-pointers.c have no main, so they compile but do not link on their own. Write a driver for each, then build it with make run FILE=driver.c EXTRA="swap-ints.c".

04-arrays-and-strings

• Char arrays
• Null termination
• Stack vs heap strings
• String literals vs allocated strings

05-io-basics

• stdin, stdout, stderr
• Buffered vs unbuffered I/O
• Why printf sometimes does not print (see stdout-buffering-fflush.c)
• Why scanf sucks (see scanf-string.c and scanf-multiple-types.c)

06-structs-unions-enums

• typedef
• Nested structs
• Alignment and padding
• Unions and tagged unions
• Enumerations

exercises

The must-do list for this phase. Nothing written yet.

• Reverse a string without library functions
• Implement strlen, strcmp, strcpy, strcat
• Build a small calculator using functions and a struct
• Debug 5 segfaults using gdb
• Visualise stack and heap memory for 10 small programs