🖋️ ft_printf

📖 About

Welcome to my implementation of the ft_printf function, a pivotal part of the 42 School curriculum. ft_printf is a formatted output conversion function, similar to the standard printf function in C, but customized to enhance flexibility and functionality. It allows you to print various types of data to the standard output with specified formats.

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🎯 Functionality

ft_printf supports a wide range of format specifiers and flags to format the output. Below is a detailed breakdown:

🔠 Format Specifiers

• %c: Prints a single character.

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

    ft_printf("Character: %c\n", 'A');
    // Output: Character: A

• %s: Prints a string.

  • Example:

    ft_printf("String: %s\n", "Hello, world!");
    // Output: String: Hello, world!

• %d or %i: Prints a signed decimal integer.

  • Example:

    ft_printf("Integer: %d\n", 42);
    // Output: Integer: 42

• %u: Prints an unsigned decimal integer.

  • Example:

    ft_printf("Unsigned integer: %u\n", 42);
    // Output: Unsigned integer: 42

• %x: Prints an unsigned hexadecimal integer (lowercase).

  • Example:

    ft_printf("Hexadecimal: %x\n", 255);
    // Output: Hexadecimal: ff

• %X: Prints an unsigned hexadecimal integer (uppercase).

  • Example:

    ft_printf("Hexadecimal: %X\n", 255);
    // Output: Hexadecimal: FF

• %p: Prints a pointer address.

  • Example:

    int *ptr = (int*)0x7ffeefbff5c8;
    ft_printf("Pointer: %p\n", ptr);
    // Output: Pointer: 0x7ffeefbff5c8

• %%: Prints a literal percent sign.

  • Example:

    ft_printf("Percent sign: %%\n");
    // Output: Percent sign: %

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🚀 Usage

To use ft_printf in your projects, include the ft_printf.h header file and link your project with the libftprintf.a static library. Then, you can start using the ft_printf function in your code.

🛠️ va_start and va_arg

The 'ft_printf' function uses the 'stdarg.h' library to handle variable arguments. Two key macros are essential for this process:

'va_start'

• Description: Initializes the variable argument list.
• Prototype: void va_start(va_list ap, last_param);
• Usage: This macro must be called before accessing any variable arguments. The 'last_param' is the last named parameter before the ellipsis (...) in the function definition.
• Example:

#include <stdarg.h>

void example_function(int fixed, ...)
{
    va_list args;
    va_start(args, fixed);
    // Access variable arguments
    va_end(args);
}

'va_arg'

• Description:: Retrieves the next argument in the variable argument list.
• Prototype:: type va_arg(va_list ap, type);
• Usage: This macro is used to access each additional argument in the list. The type specifies the type of the next argument to retrieve.
• Example:

#include <stdarg.h>

void example_function(int fixed, ...)
{
    va_list args;
    va_start(args, fixed);
    int num = va_arg(args, int);
    char ch = va_arg(args, int); // Note: char is promoted to int
    va_end(args);
}

These macros are crucial for iterating through the variable arguments provided to 'ft_printf'.

📚 Example

#include "ft_printf.h"

int main() 
{
    ft_printf("Character: %c\n", 'A');
    ft_printf("String: %s\n", "Hello, world!");
    ft_printf("Integer: %d\n", 42);
    ft_printf("Unsigned: %u\n", 42);
    ft_printf("Hex (lower): %x\n", 255);
    ft_printf("Hex (upper): %X\n", 255);
    ft_printf("Pointer: %p\n", (void *)0x7ffeefbff5c8);
    ft_printf("Percent: %%\n");
    return 0;
}

🙏 Credits

This README.md includes all the essential details, explanations, and code examples in a well-structured and visually appealing format. Feel free to modify or expand upon it as needed!