Change current file's file extension

// change fext or prompt for fully qualified buffer name
_command fe, fext() name_info(','VSARG2_EDITORCTL|VSARG2_CMDLINE)
{
   fid=p_buf_name;
   new_fext=arg(1);
   if (new_fext=='') {
      name();
      return(0);
   }
   buf_nofext=strip_filename(fid,'E');
   new_fid=buf_nofext:+'.':+new_fext;
   status=name(new_fid);
   if (status) {
      message('Fext was not changed');
      return(0);
   } else {
      save_as(new_fid);
      return(1);
   }
}