That's only useful for cooperating processes. The OP is talking about a malicious attempt to exploit a race condition.

The only thing I can think of is to use O_NOFOLLOW, which isn't portable (but should work on Linux and BSD systems): 

use Fcntl;
sysopen F, "/tmp/foo", O_RDONLY|O_NOFOLLOW;

[download]

Dave.

In reply to Re^2: opening files: link checking and race conditions by dave_the_m
in thread opening files: link checking and race conditions by danderson

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