finger(1) will retrieve information about the specified user. You give finger a username or an email address and it will try to contact the necessary server and retrieve the username, office, telephone number, and other pieces of information. Here is an example:
% finger email@example.com
finger can return the username, mail status, phone numbers, and files referred to as “dot plan” and “dot project”. Of course, the information returned varies with each finger server. The one included with Slackware returns the following information by default:
Home phone number
Work phone number
Contents of the .plan file in the user's home directory
Contents of the .project file in the user's home directory
The first four items can be set with the chfn command. It stores those values in the /etc/passwd file. To change the information in your .plan or .project file, just edit them with your favorite text editor. They must reside in your home directory and must be called .plan and .project.
Many users finger their own account from a remote machine to quickly see if they have new email. Or, you can see a user's plan or current project.
Like many commands, finger has options. Check the man page for more information on what special options you can use.