A reasonably-complete implementation of stdlib.h, and much much more.

• About
• Getting Started
• Usage
• Tests
• To Do
• Github Actions
• 42 São Paulo

This was my first project at 42 São Paulo: an implementation of many stdlib.h functions from scratch.

I've used it on most projects so far. I learned about memory manipulations, string utilities and linked lists. As a developer I've been using these functions for years in some form or another, yet I had no idea how they really work. Figuring them out was an initiation of sorts.

It has over 300 functions so far, including a heap-less printf that handles floats and long doubles. All functions have a doxygen-style documentation comment, and most have an example main. I prioritize modularity and readability: small functions with catchy names that do one thing well.

All you need is a shell and a C compiler like gcc or clang.

To compile the entire thing just clone the repo and run make:

$ git clone https://github.com/librity/ft_libft.git
$ cd ft_libft
$ make

This will generate a libft.a archive, which you can compile with any of the example files:

$ cp examples/ft_itoa.c examples/example.c
$ gcc -g -I ./includes examples/example.c libft.a
$ ./a.out

You can call most stdlib.h functions as you normally would but with the prefix ft_:

ft_putstr("Hello, world!\n");

This project is partly tested with the Unity framework. To run all tests, run make's test rule:

make tests

• Implement missing stdlib.h functions
  • atof()
  • atoi()
  • atol()
  • atoll()
  • strtod()
  • strtof()
  • strtol()
  • strtold()
  • strtoll()
  • strtoul()
  • strtoull()
  • rand()
  • srand()
  • calloc()
  • free()
  • malloc()
  • realloc()
  • abort()
  • atexit()
  • at_quick_exit()
  • exit()
  • getenv()
  • quick_exit()
  • system()
  • _Exit()
  • bsearch()
  • qsort()
  • abs()
  • div()
  • labs()
  • ldiv()
  • llabs()
  • lldiv()
  • mblen()
  • mbtowc()
  • wctomb()
  • mbstowcs()
  • wcstombs()

Norminette Github Action by @AdrianWR

Part of the larger 42 Network, 42 São Paulo is a software engineering school that offers a healthy alternative to traditional education:

• It doesn't have any teachers and classes.
• Students learn by cooperating and correcting each other's work (peer-to-peer learning).
• Its focus is as much on social skills as it is on technical skills.
• It's completely free to anyone that passes its selection process - The Piscine

It's an amazing school, and I'm grateful for the opportunity.