Re: Race conditions, mkstemp

Casper Dik (casper@fwi.uva.nl)
Sun, 11 Dec 1994 14:07:02 +0100

>
>	here is the source for mkstemp from csrg.  note the filesystem 
>must support exclusive file locking atomic to the open() for this to be 
>helpful.  as is written in the mkstemp() man page.
>
>	why wasnt O_TRUNC included.  that would hammer both soft and hard links


Because it serves no useful purpose.  A file created with O_EXCL|O_CREAT
will have 0 lenght.  If the file needs to be truncated (O_TRUNC) it
already exists, but i that case the open w/ O_CREATE|O_EXCL would fail.

O_CREATE|O_TRUNC|O_EXCL makes no sense.

Casper