void __near * __far memchr(const void __near *s, int c, size_t n);
void __far * __far _COM_memchr_f(const void __far *s, int c, size_t n);
If c is found, a pointer indicating this character is returned. If c is not found, the null pointer is returned.
This function obtains the position at which character c appears first in the first n number of characters in an object indicated by s.