Note how Perl considers the buffer to belong to Perl now.
yeah, if buf produced from malloc which means it's not belong to perl, program will throw a segment fault error. I guess Newx maybe not just a simple wrap of malloc, it does a register pointer address to perl when which assure perl could free it safely.
I think there is a way to have a PV be a pointer to memory that is not free'd by Perl, but...
yes, I think it too, that's why I post question on perlmonks. ;)
I am trying to improve my English skills, if you see a mistake please feel free to reply or /msg me a correction