These options affect the runtime behavior of gfortran.
This option has an effect only when used in the main program.
CONVERT specifier and the GFORTRAN_CONVERT_UNIT environment
variable override the default specified by -fconvert.
off_tis specified to be on that particular system. Note that specifying length as 4 limits the record length of unformatted files to 2 GB. This option does not extend the maximum possible record length on systems where
off_tis a four_byte quantity.