       ftruncate [-fileid] file newsize
              Truncate a file to have a length of at most newsize
              bytes.

              If the option -fileid is specified, file is an open
              file identifier, otherwise it is a file path.

              This   command   is  not  available  or  not  fully
              functional  if  the  underlying  operating   system
              support   is  not  available.   The  command  infox
              have_truncate will indicate  if  this  command  may
              truncate   by   file   path.    The  command  infox
              have_ftruncate will indicate if  this  command  may
              truncate by file id.

              The  -fileid  option  is  not  available on Windows
              95/NT.
