The effective user ID determines what level of access the current process has. When the effective user ID is zero (root), then the process has unrestricted access, for example.

What is Linux user ID?

A UID (user identifier) is a number assigned by Linux to each user on the system. This number is used to identify the user to the system and to determine which system resources the user can access. UIDs are stored in the /etc/passwd file: The third field represents the UID. Notice how the root user has the UID of 0.

How do I find my user ID in Linux?

4 Answers

1. Using the id command you can get the real and effective user and group IDs. id -u <username> If no username is supplied to id , it will default to the current user.
2. Using the enviroment variable. echo $UID.