File Permissions | Generated by AI
The crw-rw---- in the output of ls -alrt /dev/ttyUSB0 represents the file type and permissions for the device file /dev/ttyUSB0. Here’s a breakdown:
-
c: The first character indicates the file type.
cmeans this is a character device (as opposed tobfor block device,dfor directory, or-for regular file)./dev/ttyUSB0is a serial port device, typically used for USB-to-serial adapters. -
rw-rw—-: The next nine characters represent the permissions for the file, divided into three groups:
- rw- (positions 2-4): Permissions for the owner (root). The owner can read (
r) and write (w), but not execute (-). - rw- (positions 5-7): Permissions for the group (dialout). Members of the
dialoutgroup can also read and write, but not execute. - — (positions 8-10): Permissions for others (users not in the owner or group). Others have no permissions (no read, write, or execute).
- rw- (positions 2-4): Permissions for the owner (root). The owner can read (
Summary
/dev/ttyUSB0is a character device file.- The owner (
root) and the group (dialout) can read and write to the device. - Other users have no access.
- To interact with this device (e.g., for serial communication), your user account typically needs to be in the
dialoutgroup. You can check withgroupsand add yourself withsudo usermod -a -G dialout <username>if needed (then log out and back in).