I have a folder in sharepoint which contains excel sheets, is there a way to make it so people can only open read only files from the folder?
So when they open the excel sheet it is read only
You can simply highlight the folder, then open the Files tab in the ribbon and click on the "Shared With"-button in the Manage section.
There will pop up a modal dialog in which you have to click on "Advanced". From there you can break the inheritance and remove/add permissions to your liking.
In your case you have to change the permissions to "View Only" for the groups or users who shall only have read permission.
And you would have to make sure that the documents in the folder inherit the permissions from the folder.
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