@Tim Edwards When I read a GDS and save it in another folder, at end of that a message appears "`1 magic cell has been modified. Do you want to save exit magic of lose it ?` " What is implied by this message. Even after saving layout and trying to close magic this message appears. How to tackle this situation in magic ?

I'm not sure what cell magic thinks was modified. Possibly there are multiple top levels in the GDS file?

@Tim Edwards Can you please clarify what do you imply by

"multiple top levels in the GDS file"

in last reply ?

I didn't assert that there were multiple top level cells. I was asking whether there were. I have found some tools that are exporting some kind of metadata as an independent top level cell.

Yes, there were multiple cells in this gds. But why magic points that cell has been modified when nothing has been done. And then when

write/overwrite

is done it again asks to save ?

I think what happens is that the GDS file is marked for DRC checks when it is read in, and that's enough to mark all cells as "modified". You can run the command

gds drccheck false

before the

gds read

and I think that will make it stop asking to save the file.

I tried

gds drccheck false

as suggested but issues still persists. Even if I select

yes

to exit magic it doesn't harm since no modification is done in this case. Ideally this message should not have come. Is this interpretation correct ?

Yes, I would consider it a minor bug.