2011/11/22 KOSAKI Motohiro <kosaki.motohiro / gmail.com>:

> If I understand correctly, default umask don't allow world writable
> permission. Thus, if 0664 and 0666 make a different only when users
> changed umask intentionally. So, I don't think it's good idea to
> ignore it.

I think the default umask is 0.

http://www.bsdlover.cn/study/UnixTree/V7/usr/sys/h/param.h.html
#define	CMASK	0		/* default mask for file creation */

What do you mean about default umask?
-- 
Tanaka Akira