#include <string.h>char *strncpy(char *str1, const char *str2, size_t count);
The strncpy( ) function copies up to count characters from the string pointed to by str2 into the array pointed to by str1. str2 must be a pointer to a null-terminated string.
In C99, str1 and str2 are qualified by restrict.
If str1 and str2 overlap, the behavior of strncpy( ) is undefined.
If the string pointed to by str2 has less than count characters, nulls will be appended to the end of str1 until count characters have been copied.
Alternatively, if the string pointed to by str2 is longer than count characters, the resultant array pointed to by str1 will not be null terminated.
The strncpy( ) function returns a pointer to str1.
Related functions are memcpy( ), strchr( ), strncat( ), and strncmp( ).