Options are:
Login time is displayed as month, day, hours and minutes, unless more than six months ago, in which case the year is displayed rather than the hours and minutes.
Unknown devices as well as nonexistent idle and login times are displayed as single asterisks.
Phone numbers specified as eleven digits are printed as ``+N-NNN-NNN-NNNN''. Numbers specified as ten or seven digits are printed as the appropriate subset of that string. Numbers specified as five digits are printed as ``xN-NNNN''. Numbers specified as four digits are printed as ``xNNNN''.
If write permission is denied to the device, the phrase ``(messages off)'' is appended to the line containing the device name. One entry per user is displayed with the -l option; if a user is logged on multiple times, terminal information is repeated once per login.
Mail status is shown as ``No Mail.'' if there is no mail at all, ``Mail last read DDD MMM ## HH:MM YYYY (TZ)'' if the person has looked at their mailbox since new mail arriving, or ``New mail received ...'', `` Unread since ...'' if they have new mail.
If no options are specified, finger defaults to the -l style output if operands are provided, otherwise to the -s style. Note that some fields may be missing, in either format, if information is not available for them.
If no arguments are specified, finger will print an entry for each user currently logged into the system.
Finger may be used to look up users on a remote machine. The format is to specify a user as ``user@host '' or ``@host '' where the default output format for the former is the -l style, and the default output format for the latter is the -s style. The -l option is the only option that may be passed to a remote machine.
If standard output is a socket, finger will emit a carriage return (^M) before every linefeed (^J). This is for processing remote finger requests when invoked by fingerd(8).