When I run the the following command in a terminal I get different output. I try to find out if I am a member of the Wireshark group.
Does list wireshark
Does not list wireshark
So do I belong to the Wireshark group or not?
You haven't restarted per the instructions on that answer.
groupsis shows groups as currently applied to your user
groups $USERis asking the system to calculate the groups for that user.
This isn't a case of "trusting" one over the other. They show pointedly different things.
Groups are applied to a user when they log in. That's why my instructions are to restart or log out then in again. This makes the system apply the new group and thus allows you to use Wireshark.
Print group memberships for each USERNAME or, if no USERNAME is specified, for the current process (which may differ if the groups database has changed).
groups $USER as your current process can return different values.
groups command gives current logged in users groups in which that user belongs.
groups username allows to view groups in which username belongs to.
Try with your current username,
This is mine:
username adm cdrom sudo dip plugdev lpadmin sambashare
username@host:~$ groups username
username : username adm cdrom sudo dip plugdev lpadmin sambashare
Check with any command for whether you belong to
wireshark or not.