Printf(), Project

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What does it consist of?

This project is about to create our own printf() function, that should works like the original printf() function that we use in C, sounds a little difficult, but with the appropriate tools, we can do it.

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                Authorized functions and macros

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)

---

Above some authorized functions and macros to build our function()

Some recomendations before compilation our printf():

• As a consequence, be careful not to push any c file containing a main function in the root directory of your project (you could have a test folder containing all your tests files including main functions).

• Our main files will include your main header file (holberton.h): #include holberton.h

• You might want to look at the gcc flag -Wno-format when testing with your _printf and the standard printf.

###Now here we can see the main.c file that we used, and that you can use for test the function

#include <limits.h>
#include <stdio.h>
#include "holberton.h"

/**
 * main - Entry point
 *
 * Return: Always 0
 */
int main(void)
{
    int len;
    int len2;
    unsigned int ui;
    void *addr;

    len = _printf("Let's try to printf a simple sentence.\n");
    len2 = printf("Let's try to printf a simple sentence.\n");
    ui = (unsigned int)INT_MAX + 1024;
    addr = (void *)0x7ffe637541f0;
    _printf("Length:[%d, %i]\n", len, len);
    printf("Length:[%d, %i]\n", len2, len2);
    _printf("Negative:[%d]\n", -762534);
    printf("Negative:[%d]\n", -762534);
    _printf("Unsigned:[%u]\n", ui);
    printf("Unsigned:[%u]\n", ui);
    _printf("Unsigned octal:[%o]\n", ui);
    printf("Unsigned octal:[%o]\n", ui);
    _printf("Unsigned hexadecimal:[%x, %X]\n", ui, ui);
    printf("Unsigned hexadecimal:[%x, %X]\n", ui, ui);
    _printf("Character:[%c]\n", 'H');
    printf("Character:[%c]\n", 'H');
    _printf("String:[%s]\n", "I am a string !");
    printf("String:[%s]\n", "I am a string !");
    _printf("Address:[%p]\n", addr);
    printf("Address:[%p]\n", addr);
    len = _printf("Percent:[%%]\n");
    len2 = printf("Percent:[%%]\n");
    _printf("Len:[%d]\n", len);
    printf("Len:[%d]\n", len2);
    _printf("Unknown:[%r]\n");
    printf("Unknown:[%r]\n");
    return (0);
}

##Now what?

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Easy, we should see this output... 🙇

Let's try to printf a simple sentence.
Let's try to printf a simple sentence.
Length:[39, 39]
Length:[39, 39]
Negative:[-762534]
Negative:[-762534]
Unsigned:[2147484671]
Unsigned:[2147484671]
Unsigned octal:[20000001777]
Unsigned octal:[20000001777]
Unsigned hexadecimal:[800003ff, 800003FF]
Unsigned hexadecimal:[800003ff, 800003FF]
Character:[H]
Character:[H]
String:[I am a string !]
String:[I am a string !]
Address:[0x7ffe637541f0]
Address:[0x7ffe637541f0]
Percent:[%]
Percent:[%]
Len:[12]
Len:[12]
Unknown:[%r]
Unknown:[%r]

As you can see, dont seem difficult, but have a lot of work behind the code, try to do your own printf() function.

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