check if string in string c

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

int main() {
    char mainString[100], subString[50];

    printf("Enter the main string: ");
    fgets(mainString, sizeof(mainString), stdin);

    printf("Enter the substring to check: ");
    fgets(subString, sizeof(subString), stdin);

    if (strstr(mainString, subString) != NULL)
        printf("Substring found in the main string.\n");
    else
        printf("Substring not found in the main string.\n");

    return 0;
}