What is the fastest way to find all the file with the same inode?

Question

The only way I know is:

find /home -xdev -samefile file1

But it's really slow. I would like to find a tool like locate. The real problems comes when you have a lot of file, I suppose the operation is O(n).

Answer 1

There is no mapping from inode to name. The only way is to walk the entire filesystem, which as you pointed out is O(number of files). (Actually, I think it's θ(number of files)).

Answer 2

I know this is an old question, but many versions of find have an inum option to match a known inode number easily. You can do this with the following command:

find . -inum 1234

This will still run through all files if allowed to do-so, but once you get a match you can always stop it manually; I'm not sure if find has an option to stop after a single match (perhaps with an -exec statement?)

This is much easier than dumping output to a file, sorting etc. and other methods, so should be used when available.

Answer 3

Here's a way:

• Use find -printf "%i:\t%p or similar to create a listing of all files prefixed by inode, and output to a temporary file
• Extract the first field - the inode with ':' appended - and sort to bring duplicates together and then restrict to duplicates, using cut -f 1 | sort | uniq -d, and output that to a second temporary file
• Use fgrep -f to load the second file as a list of strings to search and search the first temporary file.

(When I wrote this, I interpreted the question as finding all files which had duplicate inodes. Of course, one could use the output of the first half of this as a kind of index, from inode to path, much like how locate works.)

On my own machine, I use these kinds of files a lot, and keep them sorted. I also have a text indexer application which can then apply binary search to quickly find all lines that have a common prefix. Such a tool ends up being quite useful for jobs like this.