I'm using Inkscape files with laser engraver. I need to identify every unclosed shape. It's very long and not totally reliable to check each shape. I wonder if a Inkscape tool exist to automatically identify unclosed shapes. Thanks for your help.

It depends what you mean by unclosed shapes.

If you are referring to simple unclosed paths then:

We know that closed path 'd' attributes must end with 'z' or 'Z'

If you use Edit>Find and the settings in the attached image.

That will select all closed paths. If you then use Edit>Select invert - the selection will change to everything which is not a closed path.

However that would also include all non path elements.

Hi. Here is my suggestion. A different reverse logic approach. 

There is a website featuring "MightyScape" which is a repository of Inkscape extensions. There they have a path extension called "Close Paths" which could suit your needs. Unfortunately, the site is currently down. However, I have included a zip file that has the key files for that extension. (I downloaded it months ago.) 

Also see the graphic files I made below for a quick example and introduction. 

This may not be the best remedy for your situation but it does work.

And worth looking into.

You will need to unzip the files and copy them to your extensions folder and then start Inkscape afresh.

The extension will be listed under Extensions > FabLab Chemnitz > Modify Existing Paths.

The website link I am referring to is

https://stadtfabrikanten.org/display/IFM/MightyScape+1.X+-+Extensions+Overview

I am using Windows 10 and Inkscape version 1.21 as my test.  I believe it eill work on later versions but am not sure about other operating systems.

I trust this helps you.

Thanks a lot Inklinea. Your suggestion was sufficient for me. It works well.

I appreciate also the website mentioned by Ken. many useful extensions!