Explain in a sufficiently detailed way how the following implementation of getchar works #define BUFSI2 1024/* getchar: simple buffered version */int getchar (void) {static char buf [BUESIZ]; static char *buf p = buf; static int n = 0; if (n == 0) {/* buffer is empty * = read (0, buf, size of buf); buf p = buf;} return (--n >= 0) ? (unsigned char) *buf p++: EOF; Explain in particular how to parse the very last instruction of the function, and what it does exactly