Of course then too you could be very unlucky and be asked to process a symlink to a file on a different filesystem which just happens to have the same inode number . . . :)

$ ls -i ./foo /tmp/foo
1808983 ./foo@   228688 /tmp/foo
$ perl -le 'print( (stat "./foo")[1] )'
228688
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So the truly paranoid might use join("|",(stat DATA)[0,1]).