Project Name

0x11. C - printf

Table of Contents

• Author Details
• Requirements
• Authorized functions and macros
• Project Description
• Compilation
• Tasks
• Known Bugs
• Collaborate

Author Details

1. Firaol Mk - firaolmekbib511@gmail.com
2. Nddatamina Assa - example@gmail.com

Requirements

• Allowed editors: vi, vim, emacs.
• All your files will be compiled on Ubuntu 20.04 LTS using gcc, using the options -Wall -Werror -Wextra -pedantic -std=gnu89.
• Your code should use the Betty style. It will be checked using betty-style.pl and betty-doc.pl.
• All your files should end with a new line.
• You are not allowed to use global variables.
• No more than 5 functions per file.
• Note that we will not provide the _putchar function for this project.
• The main.c files are used to test your functions, but you don’t have to push them to your repo.
• The prototypes of all your functions should be included in your header file called main.h.
• All your header files should be include guarded.

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)

Project Description

Write your own printf function. _printf is a custom implementation of the C programming function printf. This project is an application of the C programming knowledge that ALX School cohort 5 students have learned since starting the program on February 2022. Below are examples of how to use it:

String

• Input: _printf("%s\n", 'This is a string.');
• Output: This is a string.

Character

• Input: _printf("The first letter in the alphabet is %c\n", 'A');
• Output: The first letter in the alphabet is A

Integer

• Input: _printf("There are %i dozens in a gross\n", 12);
• Output: There are 12 dozens in a gross

Decimal:

• Input: _printf("%d\n", 1000);
• Output: 1000

Compilation

• Your code will be compiled this way.

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

• Your code will be compiled as shown above.
• 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 (main.h): #include main.h.
• You might want to look at the gcc flag -Wno-format when testing with your _printf and the standard printf. Example of test file that you could use:

alex@ubuntu:~/c/printf$ cat main.c
#include <limits.h>
#include <stdio.h>
#include "main.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);
}
alex@ubuntu:~/c/printf$ gcc -Wall -Wextra -Werror -pedantic -std=gnu89 -Wno-format *.c
alex@ubuntu:~/c/printf$ ./printf
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]
alex@ubuntu:~/c/printf$

• We strongly encourage you to work all together on a set of tests.
• If the task does not specify what to do with an edge case, do the same as printf.

Tasks

0. I'm not going anywhere. You can print that wherever you want to. I'm here and I'm a Spur for life

Write a function that produces output according to a format.

• Prototype: int _printf(const char *format, ...);
• Returns: the number of characters printed (excluding the null byte used to end output to strings).
• Write output to stdout, the standard output stream.
• format is a character string. The format string is composed of zero or more directives. See man 3 printf for more detail. You need to handle the following conversion specifiers:
  • c
  • s
  • %
• You don’t have to reproduce the buffer handling of the C library printf function.
• You don’t have to handle the flag characters.
• You don’t have to handle field width.
• You don’t have to handle precision.
• You don’t have to handle the length modifiers.

---

1. Education is when you read the fine print. Experience is what you get if you don't

Handle the following conversion specifiers:

• d
• i
• You don’t have to handle the flag characters.
• You don’t have to handle field width.
• You don’t have to handle precision.
• You don’t have to handle the length modifiers.

---

2. With a face like mine, I do better in print

Handle the following custom conversion specifiers:

• b: the unsigned int argument is converted to binary.

alex@ubuntu:~/c/printf$ cat main.c
#include "main.h"

/**
 * main - Entry point
 *
 * Return: Always 0
 */
int main(void)
{
	_printf("%b\n", 98);
	return (0);
}
alex@ubuntu:~/c/printf$ gcc -Wall -Wextra -Werror -pedantic -std=gnu89 main.c
alex@ubuntu:~/c/printf$ ./a.out
1100010
alex@ubuntu:~/c/printf$

---

3. What one has not experienced, one will never understand in print

Handle the following conversion specifiers:

• u.
• o.
• x.
• X.
• You don’t have to handle the flag characters.
• You don’t have to handle field width.
• You don’t have to handle precision.
• You don’t have to handle the length modifiers.

---

4. Nothing in fine print is ever good news

Use a local buffer of 1024 chars in order to call write as little as possible.

---

5. My weakness is wearing too much leopard print

Handle the following custom conversion specifier:

• S : 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).

alex@ubuntu:~/c/printf$ cat main.c
#include "main.h"

/**
 * main - Entry point
 *
 * Return: Always 0
 */
int main(void)
{
	_printf("%S\n", "Best\nSchool");
	return (0);
}
alex@ubuntu:~/c/printf$ gcc -Wall -Wextra -Werror -pedantic -std=gnu89 main.c
alex@ubuntu:~/c/printf$ ./a.out
Best\x0ASchool
alex@ubuntu:~/c/printf$

---

6. How is the world ruled and led to war? Diplomats lie to journalists and believe these lies when they see them in print

Handle the following conversion specifier: p.

• You don’t have to handle the flag characters.
• You don’t have to handle field width.
• You don’t have to handle precision.
• You don’t have to handle the length modifiers.

---

7. The big print gives and the small print takes away

Handle the following flag characters for non-custom conversion specifiers:

• +
• space
• #

---

8. Sarcasm is lost in print

Handle the following length modifiers for non-custom conversion specifiers:

• l
• h Conversion specifiers to handle: d, i, u, o, x, X`.

---

9. Print some money and give it to us for the rain forests

Handle the field width for non-custom conversion specifiers.

---

10. The negative is the equivalent of the composer's score, and the print the performance

Handle the precision for non-custom conversion specifiers.

---

11. It's depressing when you're still around and your albums are out of print

Handle the 0 flag character for non-custom conversion specifiers.

---

12. Every time that I wanted to give up, if I saw an interesting textile, print what ever, suddenly I would see a collection

Handle the - flag character for non-custom conversion specifiers.

---

13. Print is the sharpest and the strongest weapon of our party

Handle the following custom conversion specifier:

• r : prints the reversed string.

---

14. The flood of print has turned reading into a process of gulping rather than savoring

Handle the following custom conversion specifier:

• R: prints the rot13'ed string.

---

15.

Ensure all the above options work well together.

---

Known Bugs

The following tasks did not pass all checks.

Collaborate

To collaborate, reach us through the email addresses firaolmekbib511@gmail.com or Nddataminassa.