To show the groups a user is in on a Linux machine, you can use the groups command. This command displays the names of the groups a user belongs to.
To show the groups a user is in, you can use the following command:
groups <username>
Replace <username> with the name of the user you want to check. If you omit the username, groups will show the groups for the current user.
For example, to show the groups for the user john, you can use the following command:
groups john
This will print a list of group names, separated by spaces, indicating the groups that the user john belongs to.
You can also use the id command to show the groups a user is in. This command displays the user and group IDs for a user, as well as the groups to which the user belongs.
To show the groups a user is in using id, you can use the following command:
id -Gn <username>
Replace <username> with the name of the user you want to check. This will print a list of group names, separated by spaces, indicating the groups that the user belongs to.
Note that the specific command and options for showing the groups a user is in may vary depending on your Linux distribution and the tools it provides. Consult the documentation for your specific distribution for more information.