System.IO.openTempFile secure?

Glynn Clements glynn at
Tue May 10 04:44:17 EDT 2005

Krasimir Angelov wrote:

> > Is the function System.IO.openTempFile secure in the sense that it
> > picks the filename, tests for its existence, and creates it
> > atomically?  Either way, it's important that it's documented in
> > Haddock, IMO.
> Yes. It should be safe. The function generates a new file name and
> then tries to create file with such name. If it succeded then the file
> path and handle are returned. If the OS respond with EEXIST then the
> function tries to generate new name.

It's as safe as open(O_CREAT|O_EXCL), i.e. safe on POSIX-conformant
filesystems, unsafe on e.g. NFS.

Glynn Clements <glynn at>

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