Printf Project

This is a custom implementation of the printf() function in C. The implementation is located in the printf.c file.

Group Members

Usage

To use the _printf() function, make a main.c file and include the printf.h header file in your C program and call the function with the desired format string and arguments. The format string should include conversion specifiers and optional flags and modifiers, similar to the printf() function in the standard C library.

How the `_printf` Function Works

The _printf function in the TutTrue/printf project works in the following way:

The _printf function takes in a format string and variable arguments.
The function iterates through each character in the format string.
If the current character is not a '%', it is simply printed to the output.
If the current character is a '%', the function reads the next character to determine the conversion specifier and any associated flags/modifiers.
Based on the conversion specifier, the function extracts the corresponding function from fun which is an array of structs.
The function then formats and prints the argument to the output stream based on the conversion specifier and any associated flags/modifiers.
The function repeats steps 3-6 until the entire format string has been processed.

Note that this is a simplified overview and the actual implementation in the project may have additional details or optimizations. The source code in the printf.c file contains more details on how the function works.

Supported Conversion Specifiers

The _printf() function supports the following conversion specifiers:

%c: Character
%s: String
%S: Wide characters
%d: Signed decimal integer
%i: Signed decimal integer
%u: Unsigned decimal integer
%o: Octal integer
%x: Hexadecimal integer (lowercase)
%X: Hexadecimal integer (uppercase)
%%: Modelas
%r: Reversed string
%b: Binary
%p: Pointer

Flags and Modifiers

The _printf() function supports the following flags and modifiers:

#: causes the output to be prefixed with '0'
+: causes the output to be signed and to include a plus sign ('+') for positive values and a minus sign ('-') for negative values.
: causes the output to include a space character before positive numbers, and a minus sign ('-') before negative numbers.

Examples

Here are some examples of how to use the _printf() function:

#include "printf.h"

int main(void)
{
    char c = 'H';
    char *s = "Hello";
    int num = 123;
    unsigned int u_num = 456;
    
    _printf("Char: %c\nString: %s\nNumber: %d\n", c, s, num);
    _printf("Unsigned Number: %u\nOctal Number: %o\nHexadecimal Number: %x\n", u_num, num, num);
    
    return (0);
}

This would output:

Char: H
String: Hello
Number: 123
Unsigned Number: 456
Octal Number: 173
Hexadecimal Number: 7b

Testing

To run the test cases in the main.c file, compile the code with the following command:

gcc -Wall -Werror -Wextra -pedantic *.c -o printf

Then run the printf executable.

./printf

Bugs and Issues

If you encounter any bugs or issues with the project, please feel free to submit an issue on the project's GitHub repository.

TutTrue/printf