Ubuntu – sudo permission denied on nmcli : ubuntu server 64 raspberry pi 3

This problem happens because .mysql was created by root user using sudo and the permissions are to only read for others that are not the owner..

To simply fix this issue, change the owner of the folder to the desired user using this command in terminal:

sudo chown -R <user>:<group> .mysql

what this command does? i will explain each one of them

sudo stands for "switch user and do" which is actually changing the user to root internally for this operation

chown stands for "change owner" and it does what actually it means, of course for this command to work properly on a folder. the owner of the folder has to run it, in this case was root so sudo was necessary

-R this parameter is actually from chown and it applies the same command recursively to all sub folders/files

<user>:<group> this is just the desired owner and group we would like to assign to folder/file and its a mandatory parameter from chown. Also you have to enter the source of the folder/file next to this parameter

you can check more options for chown using man chown