printf

Creating printf from scratch

Descreption

A formatted output conversion C program completed . The program is a recreation of the C standard library function printf from scratch.

• Prototype: int _printf(const char *format, ...);

Usage

To use the _printf compile all .c files in the repository and include the header holberton.h with any main function.

Example main.c:

#include "holberton.h"

int main(void)
{
    _printf("Hello, World!");

    return (0);
}

Compilation:

$ gcc *.c -o 

Output:

$
Hello, World!
$

Return Value

Upon Working successfully the _printf returns the number of characters printed (excluding the terminating null byte used to end output to strings). If an error is encountered, the function returns -1.

Conversion Specifiers

The conversion specifier (introduced by the character %) is a character that specifies the type of conversion to be applied. The _printf function supports the following conversion specifiers:

d, i

The int argument is converted to signed decimal notation.

Example:

    _printf("%d\n", 12);
	_printf("%i\n", -7896);

Output:

12
-7896

b

The unsigned int argument is converted to signed decimal notation.

Example main.c:

    _printf("%b\n", 7);

Output:

111

o, u, x, X

The unsigned int argument is converted to unsigned octal (o), unsigned decimal (u), or unsigned hexadecimal (x and X). The letters abcdef are used for x conversions and the letters ABCDEF are used for X conversions.

Example :

    _printf("%o\n", 77);

Output:

115

c

The argument is converted to an unsigned char.

Example

    _printf("%c\n", 'A');

Output:

A

s

The char * argument is a pointer to a character array or pointer to a string is printed starting from first element to the end \0 excluding null byte

Example

    _printf("%s\n", "This is a printf function created from scratch");

Output:

This is a printf function created from scratch

S

Identical to the S conversion specifier, except any non-printable characters in the array (ie. characters with an ASCII value < 32 or >= 127) are printed as \x followed by the ASCII code value in hexadecimal

r

Reverse the char * argument

Example:

int main(void)
    _printf("r\n", "Ahmed");

Output:

demhA

R

Convert the char * to Rot13 Example:

    _printf("%R\n", "Hello, World");

Output:

Uryyb, Jbeyq

p

The address of the argument is written. The address is written in hexadecimal with a leading 0x.

Example:

    char *str = "Hello, World";
    _printf("%p\n", (void *)str);

Output:

0x561a6d7bab5d

%

A % is written. No argument is converted. The complete conversion specification is %%.

Example:

    _printf("%%\n");

Output:

%

Other Features

This function also Handle :

• The flag characters for non-custom conversion specifiers (+ SPACE #)
• The length modifiers for non-custom conversion(d, i, u, o, x, X) specifiers(l h)

Authors

• Wael Ben Hassen <benhassenwael>
• Ahmed Belhaj <Theemiss>