Input/Output Statements

The Fortran standard does not specifically does not specifically describe the implementation of I/O processing. This section provides information about processor-dependent areas and the implementation of the support for I/O.

The Fortran standard does not specifically describe the implementation of I/O processing. This section provides information about processor-dependent areas and the implementation of the support for I/O.

File Connection

OPEN Statement
The OPEN statement specifies the connection properties between the file and the unit. The Values for Keyword Specifier Variables in an OPEN Statement table indicates the keyword specifiers in an OPEN statement that are Cray Fortran compiler extensions.
Table 1. Values for Keyword Specifier Variables in an OPEN Statement
SpecifierPossible ValuesDefault Value
FORMSYSTEMUnformatted with no records marks
CONVERTLITTLE_ENDIAN, BIG_ENDIAN, CRAY, NATIVENATIVE

The FORM specifier has the following format:FORM= scalar-char-expr

A file opened with FORM=SYSTEM is unformatted and has no record marks.

The CONVERT specifier converts unformatted data between BIG- and LITTLE-ENDIAN representation. Overrides any numeric conversion specified via assign or by compilation option.

The CONVERT specifier has the following format:CONVERT="format-specifier"format-specifier describes the format of the file being opened and it only applies for that single file. It may be one of the following strings:
  • LITTLE_ENDIAN
  • Specifies little endian integer data and IEEE floating-point data. Has no effect except to override any numeric conversion specified via assign statement or by compilation option.
  • BIG_ENDIAN
  • Specifies big endian integer data and IEEE floating-point data. This has the same effect as specifying -hbyteswapio on the compilation, but it applies on a per file basis. The assign -Nswap_endian f:filename command also converts the named file to BIG_ENDIAN format.
  • CRAY
  • Indicates BIG_ENDIAN integer data and Cray floating point data of size REAL(8) or COMPLEX(8). It has the same effect as the assign command: assign -Ncray f:filename.
  • NATIVE
  • Default. Same effect as "LITTLE_ENDIAN".