printf's Introduction

_printf

This project is about creating a simplified version of the printf function in C. The _printf function is a custom implementation of the C programming language's printf function, which is part of the standard library. The function is variadic, meaning it accepts a variable number of arguments.

Authorized functions and macros

The following functions and macros are used in this project:

write (man 2 write)
malloc (man 3 malloc)
free (man 3 free)
va_start (man 3 va_start)
va_end (man 3 va_end)
va_copy (man 3 va_copy)
va_arg (man 3 va_arg)

Compilation

The code is compiled this way:

gcc -Wall -Werror -Wextra -pedantic -std=gnu89 *.c

Usage

The _printf function can be used similarly to the printf function. It takes a format string and a variable number of arguments, and writes the output to stdout (the standard output stream).

Here is a basic usage example:

#include "main.h"

int main(void)
{
    _printf("Hello, world!\n");
    return (0);
}

Format Specifiers

The _printf function supports the following format specifiers:

%c: Character
%s: String of characters
%d or %i: Signed decimal integer
%b: Unsigned binary
%u: Unsigned decimal integer
%o: Unsigned octal
%x: Unsigned hexadecimal integer (lowercase)
%X: Unsigned hexadecimal integer (uppercase)
%S: Custom conversion specifier, prints the string. Non printable characters (0 < ASCII value < 32 or >= 127) are printed this way: \x, followed by the ASCII code value in hexadecimal (upper case - always 2 characters)
%p: Pointer address
%r: Custom conversion specifier, prints the reversed string
%R: Custom conversion specifier, prints the Rot13'ed string