       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 identi-
              fier, 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 com-
              mand infox have_truncate will indicate if this command may trun-
              cate  by file path.  The command infox have_ftruncate will indi-
              cate if this command may truncate by file id.

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