42_printf

Statement of the project (in Spanish / English)

Introduction

This project aims to recreate the functionality of the printf function from the C standard library (<stdio.h>). The goal is to implement this function using variadic arguments, providing support for various format specifiers and handling different types of data.

Project Objectives

Understand and implement variadic functions in C.
Handle different format specifiers to print various data types.
Manage multiple flags and their combinations for formatting output.

Variadic Functions and Arguments

Variadic functions are functions that accept a variable number of arguments. In C, this is achieved using the stdarg.h library, which provides macros to handle the arguments.

Key Macros

va_list : A type to hold the information needed to retrieve the additional arguments.
va_start : Initializes a va_list variable to retrieve the additional arguments.
va_arg : Retrieves the next argument in the list.
va_end : Cleans up the va_list variable.

Mandatory part

Function Prototype

The prototype of the function is the following:

int	ft_printf(const char *str, ...);

Supported Format Specifiers

The ft_printf function must handle the following format specifiers:

Specifier	Description
'%c'	Prints a single character
'%s'	Prints a string
'%p'	Prints a pointer in hexadecimal format
'%d'	Prints a decimal (base 10) number
'%i'	Prints an integer in base 10
'%u'	Prints an unsigned decimal (base 10) number
'%x'	Prints a number in hexadecimal (base 16) lowercase format
'%X'	Prints a number in hexadecimal (base 16) uppercase format
'%c'	Prints a single character
'%%'	Prints a percent sign

Bonus part

The bonus part extends the functionality to handle various flags for formatting:

Supported Flags

Flags	Description
'-'	Right-padding with spaces
'0'	Left-padding with zeroes
'.'	Indicates precision
'#'	Adds "0x" to a hexadecimal number
' '	Adds a space before a positive number
'+'	Adds a sign (+/-) before a number

Format

The general format for the ft_printf function with flags is:

%[flags][width][.precision]type

Implementation Steps

Parsing the Format String: Identify and extract format specifiers and flags from the input string.
Handling Variadic Arguments: Use va_list to manage a variable number of arguments passed to the function.
Implementing Specifiers: Write functions to handle each format specifier, converting the arguments to their respective string representations.
Managing Flags: Implement the logic to handle different flags and apply them to the formatted output.
Combining Results: Construct the final output string by combining the processed arguments and print it.

Eleee28/42_printf