It appears that the links in /proc/*/fd are canonified, i.e. if you open a symlink to foo, then /proc/$$/fd/xx will also point to foo: 
$ perl -le 'symlink("foo","bar") o
r die $!; open F, ">bar" or die $!; print readlink("/proc/$$/fd/".file
+no(F))'
/tmp/foo

[download]
Therefore, you can be sure that the paths in the proc filesystem aren't symlinks. Hard links are a harder problem. fuser seems to always get it right, though.

In reply to Re^6: How to detect if file is in use? by betterworld
in thread How to detect if file is in use? by blazar

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