strnlen—character string length #include <string.h>
size_t strnlen(const char *str, size_t n);
Description
The strnlen function works out the length of the string
starting at *str by counting chararacters until it
reaches a NUL character or the maximum: n number of
characters have been inspected.
Returns
strnlen returns the character count or n.
Portability
strnlen is a GNU extension.
strnlen requires no supporting OS subroutines.