chfn changes user fullname, office number, office extension, and home phone number information for a user's account. This information is typically printed by finger and similar programs. A normal user may only change the fields for their own account, the super user may change the fields for any account. Also, only the super user may use the -o option to change the undefined portions of the GCOS field.
The only restrictions placed on the contents of the fields is that no control characters may be present, nor any of comma, colon, or equal sign. The other field does not have this restriction, and is used to store accounting information used by other applications.
If none of the options are selected, chfn operates in an interactive fashion. The prompts and expected input in interactive mode are implementation-dependent and should not be relied upon.
As it is possible for the system to be configured to restrict which fields a non-privileged user is permitted to change, applications should be written to gracefully handle these situations.
sets the user's full name.
sets the user's room number.
sets the user's work phone number.
sets the user's home phone number.
sets the contents of the other field.