2.3.21 char * strncpy_P
char * strncpy_P(char *, const char *, size_t)
The strncpy_P() function is similar to strcpy_P() except that not more than n bytes of src are copied. Thus, if there is no null byte among the first n bytes of src, the result will not be null-terminated.
In the case where the length of src is less than that of n, the remainder of dest will be padded with nulls.
Remember:
The strncpy_P() function returns a pointer to the destination string dest.