printf

The awesome printf() function

printf - formatted output conversion, display character to stdout.

Author

printf() is written and maintained by Victor Doledji (@gmail.com) and Samadou Ouro-agorouko (souroagorouko@gmail.com).

How to use it ?

First all, clone this repositoy to your local machine.
Then create a c file like "main.c" at the root of your folder.
write the main function to test our printf fucntion.
Run "gcc -Wall -Werror -Wextra -pedantic -std=gnu89 *.c && ./printf" to compile and run.

Description

The printf() function produce output according to a format as described below. Also, write output to stdout, the standard output stream.

The printf() function write the output under the control of a format string that specifies how subsequent arguments (or arguments accessed via the variable-length argument facilities of stdarg(3) are converted for output.

Format of the format string

The format string is a character string, beginning and ending inits initial shift state, if any. The format string is composed of zero or more directives: ordinary characters (not %), which are copied unchanged to the output stream; and conversion specifications, each of which results in fetching zero or more subsequent arguments. Each conversion specification is introduced by the character % and ends with conversion specifier.

Conversion specifiers

A character that specifies the type of conversion to be applied. The conversion specifiers and their meaning are:

d, i: The int argument should be signed decimal notation, and the resulting number is written.
c: The int argument is converted to a char, and the resulting character is written.
s: The const char * argument is expected to be a pointer to an array of character type (pointer to a string). Characters from the array are written up to (but not including) a terminating null byte ('\0').
%: A '%' is written. No argument is converted. The complete conversion specification is '%%'.

int print_format (const char *format, ...)

This function gets a format to be printed and a variadic arguments list, next to check if the format is valid or invalid and according with the verification the resulting output is written to the standard output stream and returns the format length.

Return Value

Upon successful return, the printf() function return the number of characters printed (excluding the null byte used to end output to strings).

If an output error is encountered, a negative value is returned.

Examples

#include "main.h"

printf("Hello Victor"); // the output will be: Hello Victor

printf("%c", 'S'); // the output will be: S

printf("%s", "Victor is a guru of C programming"); // the output will be: Victor is a guru of C programming

printf("%!\n"); // the output will be '%!'

printf("Complete the sentence: You %s nothing, Jon Snow.\n", "know"); // the output will be: Complete the sentence: You know nothing, Jon Snow.

_printf("% s", "Hello"); // the output will be: Hello

_printf("% k"); // the output will be: % k

hydromelvictor / printf