strncpy()

char * fl::strncpy	(	char *	dest,
		const char *	src,
		size_t	n )

Definition at line 50 of file cstring.cpp.hpp.

                                                                  {
    // Unlike ::strncpy, this ALWAYS null-terminates: it copies at most n
    // characters from src, then writes a terminator at dest[copied]
    // (copied <= n). Callers pass n = capacity - 1 (dest sized >= n+1),
    // so the terminator is always in bounds. This closes the classic
    // strncpy hazard where a source of length >= n leaves dest
    // unterminated and downstream string walks run off the buffer
    // (FastLED#3588: an unterminated HTTP request URI let a query-strip
    // loop write a stray null byte one past a heap allocation).
    size_t i = 0;
    for (; i < n && src[i] != '\0'; ++i) {
        dest[i] = src[i];
    }
    dest[i] = '\0';
    // Preserve ::strncpy's zero-padding of the remaining destination
    // bytes so callers relying on that behavior are unaffected.
    for (size_t j = i + 1; j < n; ++j) {
        dest[j] = '\0';
    }
    return dest;
}

References FL_NO_EXCEPT.