print integer to stdout using write or putchar?

To print an integer to stdout in the C programming language, you can use either the write or putchar functions.

Using the write function:

The write function is a system call that writes data to a file descriptor. In this case, we will use file descriptor 1, which represents stdout. Here are the steps to print an integer using write:

1. Convert the integer to a string using the sprintf function.
2. Determine the length of the string using the strlen function.
3. Use the write function to write the string to stdout.

Here is an example code snippet that demonstrates this approach:

#include <stdio.h>
#include <string.h>
#include <unistd.h>

int main() {
    int num = 123;
    char str[20];
    sprintf(str, "%d", num);
    int len = strlen(str);
    write(1, str, len);
    return 0;
}

Using the putchar function:

The putchar function is a standard library function that writes a character to stdout. To print an integer using putchar, you need to convert each digit of the integer to a character and then write each character to stdout. Here are the steps:

1. Initialize a variable num with the integer value.
2. Create a loop that extracts each digit of the integer.
3. Convert each digit to a character using the ASCII representation.
4. Use the putchar function to write each character to stdout.

Here is an example code snippet that demonstrates this approach:

#include <stdio.h>

void printInteger(int num) {
    if (num < 0) {
        putchar('-');
        num = -num;
    }

    if (num / 10) {
        printInteger(num / 10);
    }

    putchar(num % 10 + '0');
}

int main() {
    int num = 123;
    printInteger(num);
    return 0;
}

These are two different approaches you can use to print an integer to stdout in the C programming language using the write or putchar functions.