       chgrp [-fileid] group filelist
              Set  the group id of each file in the list filelist
              to group, which can be either a  group  name  or  a
              numeric group id.

              If  the  option -fileid is specified, filelist is a
              list of open file identifiers rather than a list of
              file  names.   This  option is not available on all
              Unix systems.  Use the infox have_fchown command to
              determine if this functionallity is available.

              This command is provided by Extended Tcl.
