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FBTAB(5) File Formats Manual FBTAB(5)

fbtabchange device protection upon login

The fbtab file contains lines which specify how the permissions and ownership of various system files should be changed based on the user's login device name.

Comments start with a ‘#’ and extend to the end of the line. Blank lines or lines with only a comment are ignored.

All other lines consist of three fields delimited by whitespace.

Login Device
The device you have logged in on (e.g., “/dev/ttyv0”).
File Permission
An octal permission number (0600), as used by chmod(2).
Other devices
The final field is a colon (‘:’) delimited list of devices (e.g., “/dev/console:/dev/fd0a”). All device names are absolute paths. A path that ends in “/*” refers to all directory entries except “.” and “..”.

The fbtab file is used by login(1) to chown(2) the specified files to the user who has performed a login. Additionally, chmod(2) is used to set the devices to the specified permission. When a user logs out, init(8) is responsible for performing the inverse operation, which results in the files once again belonging to root.


login(1), login_fbtab(3), init(8)

Guido van Rooij

September 8, 2014 OpenBSD-6.8