http://gcc.gnu.org/onlinedocs/gfortran/GFORTRAN_005fCONVERT_005fUNIT.html
Result (on x86_64/Linux): GFORTRAN_CONVERT_UNIT set to "" default:"LITTLE_ENDIAN" native:"LITTLE_ENDIAN" swap:"BIG_ENDIAN" little_endian:"LITTLE_ENDIAN" big_endian:"BIG_ENDIAN" GFORTRAN_CONVERT_UNIT set to "BIG_ENDIAN" ! same with "big_endian" default:"LITTLE_ENDIAN" native:"LITTLE_ENDIAN" swap:"BIG_ENDIAN" little_endian:"LITTLE_ENDIAN" big_endian:"BIG_ENDIAN" Test program program conv implicit none character(20) :: ch CALL GET_ENVIRONMENT_VARIABLE('GFORTRAN_CONVERT_UNIT', ch) print '(3a)', 'GFORTRAN_CONVERT_UNIT set to "',trim(ch),'"' open(11,form='unformatted'); inquire(11,convert=ch) print '(3a)', 'default:"',trim(ch),'"'; close(11,status='delete') open(12,form='unformatted',convert="native") inquire(12,convert=ch) print '(3a)', 'native:"',trim(ch),'"'; close(12,status='delete') open(13,form='unformatted',convert="swap") inquire(13,convert=ch) print '(3a)', 'swap:"',trim(ch),'"'; close(13,status='delete') open(14,form='unformatted',convert="little_endian") inquire(14,convert=ch) print '(3a)', 'little_endian:"',trim(ch),'"'; close(14,status='delete') open(15,form='unformatted',convert="big_endian") inquire(15,convert=ch) print '(3a)', 'big_endian:"',trim(ch),'"'; close(15,status='delete') end program conv -- Summary: GFORTRAN_CONVERT_UNIT is ignored Product: gcc Version: 4.3.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: fortran AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: burnus at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31917