Code it in C program. It is urgent please

2) Write a function void Star_fill (char str1[])) that will fill up a variable-length string with stars to its maximum size. For example, if the array is char str [12] and user input is CSE115. Star_fill() function would add five stars (one of which would overwrite the null character) and finish the string with the null character. Be sure your function would work if no star fill were necessary. Input: CSE115 Output: CSE115*****