Let's begin by creating a function that takes a string as input and reverses its characters. We'll do this by swapping characters from the beginning and end of the string, moving towards the center.

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

void reverseString(char *str) {
    int len = strlen(str);
    int i;
    char temp;
    for (i = 0; i < len / 2; i++) {
        temp = str[i];
        str[i] = str[len - i - 1];
        str[len - i - 1] = temp;
    }
}

int main() {
    char str[100];
    printf("Enter a string: ");
    fgets(str, sizeof(str), stdin);
    str[strcspn(str, "\n")] = 0;  // Remove newline character if present
    reverseString(str);
    printf("Reversed string: %s", str);
    return 0;
}
            

This function utilizes a for loop to swap characters from opposite ends of the string, efficiently reversing the string in-place.

Compile the code using GCC or another preferred C compiler:

gcc -o stringReverse stringReverse.c

Execute your program to test the string reversal:

./stringReverse

This command runs your compiled program, prompting you to enter a string and then displaying its reversed version.