The strlcpy() function copies at most dstsize-1 characters (dstsize being the size of the string buffer dst) from src to dst, truncating src if necessary. The result is always null-terminated.
The strlcat() function appends at most (dstsize- strlen(dst)-1) characters of src to dst (dstsize being the size of the string buffer dst). The initial character of src overrides the null character at the end of dst. The function returns the sum the of lengths of the two strings strlen(dst)+strlen(src).