\fBchfn\fR changes user fullname, office number, office extension, and home phone number information for a user's account\&. This information is typically printed by \fBfinger\fR(1) and similar programs\&. A normal user may only change may only change the fields for her own account, subject to the restrictions in \fI/etc/login\&.defs\fR\&. (The default configuration is to prevent users from changing their fullname\&.) The super user may change any field for any account\&. Additionally, only the super user may use the \fB\-o\fR option to change the undefined portions of the GECOS field\&.
.PP
The only restriction placed on the contents of the fields is that no control characters may be present, nor any of comma, colon, or equal sign\&. The \fIother\fR field does not have this restriction, and is used to store accounting information used by other applications\&.
.PP
If none of the options are selected, \fBchfn\fR operates in an interactive fashion, prompting the user with the current values for all of the fields\&. Enter the new value to change the field, or leave the line blank to use the current value\&. The current value is displayed between a pair of \fI[ ]\fR marks\&. Without options, chfn prompts for the current user account\&.
