I would like to add special user (ideally manually add to files controlling users and groups, so not use any utilities for this, because my system is read only) with these specifications (my system is Debian):
- this user will be used just for running specific program
- he can't log in to system as a standard user and any other method such as ssh, ftp, etc (so this user will be just for running specific program ONLY, so no other action is allowed. This user will be used to run a script via rc.local and from another python script)
- not allowed to become sudo/su
- he must be able to access /dev/spidev1.0
- this user doesn't need to have his own /home/thisuser dir
- he can't be able to access files in dirs such as /home/otherusers
How can I do this please? Any step by step guide?