Exercise 02

Exercise 02: Displaying Characters of a String

Your second task is to write a C function called my_putstr that displays, one-by-one, the characters of a string. The address of the string’s first character will be found in the pointer passed as a parameter to the function.

// Function prototype
int my_putstr(const char *str);

Hints

Before diving into the solution, here are some hints to help you tackle the problem:

• Understand how strings are represented in C using null-terminated character arrays.
• Learn about pointer arithmetic and how it can be used to traverse through a string.
• Consider using a while loop to iterate through the characters of the string.
• Use the provided my_putchar function to output each character.

These hints should give you a good starting point to work on the exercise. Good luck!

Solution

#include <unistd.h>

void my_putchar(char c)
{
    write(1, &c, 1);
}

/*
* This function, my_putstr, displays the characters of a string
* one-by-one using the my_putchar function.
*/
int my_putstr(const char *str) {
    // Loop through the string until the null terminator '\0' is reached
    for (int i = 0; str[i] != '\0'; i++) {
        // Output the current character using my_putchar function
        my_putchar(str[i]);
    }

    // Return 0 to indicate successful execution
    return 0;
}

Explanation:

• In this solution, we use a for loop to iterate through each character of the string passed as a parameter.
• The loop continues until the null terminator '\0' is encountered, indicating the end of the string.
• Within the loop, we use indexing (str[i]) to access each character of the string and pass it to the my_putchar function for output.
• This process continues until all characters of the string have been printed.