/Printf

My Printf project - 42SP

Primary LanguageC

Let's talk about: PRINTF 💬

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🦮 Summary: 🦮

🔗 What's the PRINTF?

🔗 Mandatory part

🔗 cspdiuxX%

🔗 Variadic function

🔗 How to use the printf?

🔗 Bonus part

🔗 How to use my printf?

What is PRINTF? 🤔

libft

The ft_printf project involves recreating the printf function in C. Students are tasked with implementing their own version of printf, which can format and print text to the console, handling format specifiers such as %d, %s, %f, etc. Along with their respective flags and modifiers. Through this project, students gain a deeper understanding of string manipulation in C, variadic function variadic arguments handling, pointer manipulation, and the implementation of standard library functions. Some challenges students may parsing format strings correctly, handling various format specifiers and flags, and ensuring proper error handling.

The good way to adquire a first knowledge about the project is the video bellow:



Mandatory part 📑

  • The prototype of ft_printf should be int ft_printf(const char *, ...);
  • You have to recode the libc’s printf function
  • It must not do the buffer management like the real printf
  • It will manage the following conversions: cspdiuxX%

cspdiuxX%:

  • C: print a single character
  • S: print a string of characters
  • P: print a pointer address
  • D: print a decimal (base 10) number
  • I: print an integer in base 10
  • U: print an unsigned decimal (base 10) number
  • x: print a number in hexadecimal (base 16) format in lowercase
  • X: print a number in hexadecimal (base 16) format in uppercase
  • %: print a percent sign (%)

Variadic function 📦

The variadic function is a function that can accept a variable number of arguments. The stdarg.h header file provides a way to access the arguments passed to a function that takes a variable number of arguments. The stdarg.h header file provides a way to access the arguments passed to a function that takes a variable number of arguments. To understand more about variadic arguments and variadic function you can access the link bellow:



But in resume to use a variadic function you need to declare a va_list type variable in the function, and then use the va_start, va_arg, and va_end macros to access the arguments.


How to use the printf? 📌

The printf function is a variadic function, which means it can accept a variable number of arguments. The first argument is a format string that specifies how to format the remaining arguments. The format string can contain plain text and format specifiers. The format specifiers are placeholders that are replaced with the values of the remaining arguments.

For example:

#include <stdio.h>

int main() {
    int num = 42;
    printf("The answer is %d\n", num);
    return 0;
}

The format string "The answer is %d\n" contains the format specifier %d, which is replaced with the value of the variable num. The output of the program is "The answer is 42".


Bonus Part 📑

The bonus part of the project is to handle the following flags and modifiers:

  • + : print a plus sign (+) in front of positive numbers and a minus sign (-) in front of negative numbers
  • 0 : print zeros (0) instead of spaces when padding numbers
  • # : print the number in an alternative format
  • : print a space in front of positive numbers
  • - : left-align the number within the specified width
  • . : specify the number of decimal places to print for floating-point numbers

How to use my printf?

First, you will be clone my repository:


  • With a SSH key:
git clone git@github.com:Chrystian-Natanael/Printf.git

  • Whithout a SSH key:
git clone https://github.com/Chrystian-Natanael/Printf.git

After that, you will be compile the project with the command bellow:

  • For mandatory part:
make

  • For bonus part:
make bonus

Now you can use the libftprintf.a library in your project. You can use the ft_printf function as you would use the printf function from the standard library.

  • Main example:
#include "ft_printf.h"

int main() {
    int num = 42;
    ft_printf("The answer is %d\n", num);
    return 0;
}

To compile the program, you will be use the command bellow:

gcc main.c libftprintf.a