Custom printf helper function using Win32 API instead of CRT function (printf)

debug_print.c

#include <windows.h> // Include Windows API

// Debug print toggle, comment this to disable debug print statements
#define DEBUG_PRINT

// Function to write a string to the console
void write_to_console(const char* str, int length) {
    HANDLE hConsole = GetStdHandle(STD_OUTPUT_HANDLE);
    DWORD written;
    WriteConsoleA(hConsole, str, length, &written, NULL);
}

// Custom function to convert integer to string
void my_itoa(int value, char* str, int base) {
    int i = 0;
    int isNegative = 0;

    // Handle 0 explicitly
    if (value == 0) {
        str[i++] = '0';
        str[i] = '\0';
        return;
    }

    // Handle negative integers
    if (value < 0 && base == 10) {
        isNegative = 1;
        value = -value;
    }

    // Process individual digits
    while (value != 0) {
        int remainder = value % base;
        str[i++] = (remainder > 9) ? (remainder - 10) + 'a' : remainder + '0';
        value = value / base;
    }

    // Append negative sign for negative numbers
    if (isNegative) {
        str[i++] = '-';
    }

    // Null-terminate the string
    str[i] = '\0';

    // Reverse the string
    for (int j = 0; j < i / 2; j++) {
        char temp = str[j];
        str[j] = str[i - j - 1];
        str[i - j - 1] = temp;
    }
}

// Custom function to convert pointer to hexadecimal string
void my_ptrtoa(void* ptr, char* str, int max_size) {
    unsigned long long value = (unsigned long long)ptr;
    int i = 0;

    if (max_size < 3) {
        return;
    }

    if (value == 0) {
        str[i++] = '0';
    }
    else {
        while (value != 0 && i < max_size - 1) {
            int remainder = value % 16;
            str[i++] = (remainder > 9) ? (remainder - 10) + 'a' : remainder + '0';
            value = value / 16;
        }
    }

    for (int j = 0; j < i / 2; j++) {
        char temp = str[j];
        str[j] = str[i - j - 1];
        str[i - j - 1] = temp;
    }

    str[i] = '\0';
}

// Print function that accepts a format string and various arguments
void printd(const char* format, ...) {
#ifdef DEBUG_PRINT
    char buffer[256];
    char temp[64]; // Temporary buffer for formatted output
    int i = 0, j = 0;

    va_list args;
    va_start(args, format); // Initialize va_list

    while (format[i] != '\0') {
        if (format[i] == '%') {
            i++;
            if (format[i] == 's') { // Handle string
                const char* str = va_arg(args, const char*);
                while (*str != '\0' && j < sizeof(buffer) - 1) {
                    buffer[j++] = *str++;
                }
            }
            else if (format[i] == 'd') { // Handle integer
                int num = va_arg(args, int);
                my_itoa(num, temp, 10);
                for (int k = 0; temp[k] != '\0'; k++) {
                    buffer[j++] = temp[k];
                }
            }
            else if (format[i] == 'c') { // Handle character
                char ch = (char)va_arg(args, int);
                buffer[j++] = ch;
            }
            else if (format[i] == 'p') { // Handle pointer
                void* ptr = va_arg(args, void*);
                my_ptrtoa(ptr, temp, sizeof(temp));
                for (int k = 0; temp[k] != '\0'; k++) {
                    buffer[j++] = temp[k];
                }
            }
            else {
                // Handle unknown specifier
                buffer[j++] = '%';
                buffer[j++] = format[i];
            }
        }
        else {
            buffer[j++] = format[i];
        }
        i++;
    }

    buffer[j] = '\0';
    write_to_console(buffer, j);
    va_end(args); // Clean up va_list
#endif
}

// Main function to demonstrate the print functionality
int main() {
    char a[] = "test";
    int num = 42;
    char ch = 'A';
    printd("String is: %s\nInteger is: %d\nCharacter is: %c\nPointer is: %p\n", a, num, ch, &num);

    return 0;
}