who - Who is on the system
who [ pattern ] [ >outputfile ]
who am i
Who with no arguments displays a full listing of all the members who have accounts on the system. Shown are their login names, real names, locations, and last login times.
If who is given a pattern as a search condition, it prints out only those entries in the member list where the pattern is matched. This is normally used for selection of a single user by using their login name, but you may also find other parts of the entry such as cities, states, or last login dates and times. If a pattern requires space characters, enclose it in quotes.
When who finds an entry whose login matches the pattern, it displays that user’s resume file if it exists in their directory. If the pattern given is “all”, who displays a full member list and attempts to print out the resume files for every member.
If the last argument given is a file name beginning with a ‘>’, output from who is directed into the file.
“who am i” displays your Internet address and full name.