Foundations - Low-level programming & Algorithm ― Hatching out by Julien Barbier, co-founder at Holberton School.
- Write your own
printffunction.
- Allowed editors: vi, vim, emacs.
- All your files will be compiled on Ubuntu 14.04 LTS.
- Your programs and functions will be compiled with gcc 4.8.4 using the flags -Wall -Werror -Wextra and -pedantic.
- All your files should end with a new line.
- A README.md file, at the root of the folder of the project is mandatory.
- Your code should use the Betty style. It will be checked using betty-style.pl and betty-doc.pl.
- You are not allowed to use global variables.
- No more than 5 functions per file.
- In the following examples, the main.c files are shown as examples. You can use them to test your functions, but you don’t have to push them to your repo (if you do we won’t take them into account). We will use our own main.c files at compilation. Our main.c files might be different from the one shown in the examples.
- The prototypes of all your functions should be included in your header file called holberton.h
- Don’t forget to push your header file.
- All your header files should be include guarded.
- Note that we will not provide the_putchar function for 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)
- Your code will be compiled this way:
$ gcc -Wall -Werror -Wextra -pedantic *.c
- 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. Example of test file that you could use:
alex@ubuntu:~/c/printf$ cat main.c
#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);
}
alex@ubuntu:~/c/printf$ gcc -Wall -Wextra -Werror -pedantic -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
0. I'm not going anywhere. You can print that wherever you want to. I'm here and I'm a Spur for life
- 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
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
- b: the unsigned int argument is converted to binary
- 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
- 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)
7. How is the world ruled and led to war? Diplomats lie to journalists and believe these lies when they see them in print
- 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
- +
- space
- #
- l
- h Conversion specifiers to handle: d, i, u, o, x, X
13. Every time that I wanted to give up, if I saw an interesting textile, print what ever, suddenly I would see a collection.
- r : prints the reversed string
- R: prints the rot13'ed string
- GitHub repository: printf
- Camilo Bayona Orduz - Initial work - cbayonao
- Cristiam Camilo Baquero - Initial work - camilooob
- Follow the framework
- Hat tip to anyone whose code was used
- Inspiration
- etc