C program. No print statements in the functions

Write a function to determine if a given string str contains a substring subStr . The function should return true if subStr appears anywhere inside str, false otherwise. int strContains (const char *str, const char *subStr); Write a function that takes two strings and concatenates them together into a new string. char *concatenate(const char *s, const char *t); Write a function that takes two strings, s and t and appends t to S returning the result as a new string. char *append (const char *s, const char *t); Write a function that takes two strings, s and t and prepends t to s returning the result as a new string. char *prepend(const char *s, const char *t)