Re: Creating lock file for compilers that don't support -c -o

[Paul Jarc]

Bob Friesenhahn <address@hidden> wrote:
> Creating a symbolic link requires testing for an existing file, and
> then (if the file does not exist) creating a new file, and a
> directory entry to reference it.  This requires multiple network
> transactions with an opportunity for race-conditions.

open() with O_CREAT|O_EXCL also creates a new file, yet that does not
subject it to race conditions.  symlink() has equivalent semantics to
O_CREAT|O_EXCL.  It may be that some network filesystems fail to
preserve the atomicity; I wouldn't know.  But at least for local
filesystems, I don't see any problems with symlinks.


paul