OPEN Statement Specifiers

The OPEN statement connects an external file to a unit, creates a new file and connects it to a unit, creates a preconnected file, or changes certain properties of a connection. For more information, see OPEN.

The following table summarizes details about the OPEN statement specifiers and it contains links to their descriptions:

OPEN Statement Specifiers and Values

Specifier

Values

Function

Default

ACCESS

'DIRECT'

'SEQUENTIAL'

'STREAM'

'APPEND'

Access mode

'SEQUENTIAL'

ACTION (or MODE)

'READ'

'WRITE'

'READWRITE'

File access

'READWRITE'

ASSOCIATEVARIABLE

A scalar integer variable

Next direct access record

No default

ASYNCHRONOUS

'YES'

'NO'

Asynchronous I/O

'NO'

BLANK

'NULL'

'ZERO'

Interpretation of blanks

'NULL'

BLOCKSIZE

A scalar numeric expression

Physical I/O transfer size

131,072 bytes

BUFFERCOUNT

A scalar numeric expression

Number of I/O buffers

One

BUFFERED

'YES'

'NO'

Buffering for WRITE operations; buffering for READ operations on variable length, unformatted, input records

'NO'

Note: The default is also 'NO' when reading variable length, unformatted records whose length exceeds that of the block size specified for the file.

CARRIAGECONTROL

'FORTRAN'

'LIST'

'NONE'

Print control

Formatted: 'LIST'

Note: If you specify compiler option vms, and the unit is connected to a terminal, the default is 'FORTRAN'.

Unformatted: 'NONE'

CONVERT

'LITTLE_ENDIAN'

'BIG_ENDIAN'

'CRAY'

'FDX'

'FGX'

'IBM'

'VAXD'

'VAXG'

'NATIVE'

Numeric format specification

'NATIVE'

DECIMAL

'COMMA'

'POINT'

Decimal edit mode

'POINT'

DEFAULTFILE

A scalar default character expression

Default file pathname

Current working directory

DELIM

'APOSTROPHE'

'QUOTE'

'NONE'

Delimiter for character constants

'NONE'

DISPOSE (or DISP)

'KEEP' or 'SAVE'

'DELETE'

'PRINT'

'PRINT/DELETE'

'SUBMIT'

'SUBMIT/DELETE'

File disposition at close

'KEEP'

ENCODING

'UTF-8'

'DEFAULT'

Encoding form for a file

'DEFAULT'

ERR

A statement label

Error transfer control

No default

FILE (or NAME)

A scalar default character expression

File pathname (file name)

fort.n, where n is the unit number.

FORM

'FORMATTED'

'UNFORMATTED'

'BINARY'

Format type

Depends on ACCESS setting

IOFOCUS

.TRUE.

.FALSE.

Active window in QuickWin application

.TRUE.

Note: If unit '*' is specified, the default is .FALSE.; otherwise, the default is .TRUE..

IOSTAT

A scalar integer variable

I/O status

No default

MAXREC

A scalar numeric expression

Direct access record limit

No limit

NEWUNIT

A scalar integer variable

Returns automatically chosen, unused, unit number

No default

NOSHARED

No value

File sharing disallowed

Linux: SHARED

Windows: Not shared

ORGANIZATION

'SEQUENTIAL'

'RELATIVE'

File organization

'SEQUENTIAL'

PAD

'YES'

'NO'

Record padding

'YES'

POSITION

'ASIS'

'REWIND'

'APPEND'

File positioning

'ASIS'

READONLY

No value

Write protection

No default

RECL

(or RECORDSIZE)

A scalar numeric expression

Record length

Depends on RECORDTYPE,ORGANIZATION, and FORM settings

Note: On Linux* systems, the default depends only on the FORM setting.

RECORDTYPE

'FIXED'

'VARIABLE'

'SEGMENTED'

'STREAM'

'STREAM_CR'

'STREAM_LF'

Record type

Depends on ORGANIZATION, CARRIAGECONTROL, ACCESS, and FORM settings

ROUND

'UP'

'DOWN'

'ZERO'

'NEAREST'

'COMPATIBLE'

'PROCESSOR_DEFINED'

Rounding mode

'PROCESSOR_DEFINED' - this corresponds to 'NEAREST' as in the ISO/IEC 60559:2020 standard specification for roundTiesToEven

SHARE

'DENYRW'

'DENYWR'

'DENYRD'

'DENYNONE'

File locking

'DENYWR'

Note: The default differs under certain conditions (see SHARE Specifier).

Other notes:

  • 'DENYWR': On Linux* systems, the default depends only on the FORM setting.

  • 'DENYRD': Applies to Windows.

SHARED

No value

File sharing allowed

Linux*: SHARED

Windows: Not shared

SIGN

'PLUS'

'SUPPRESS'

'PROCESSOR_DEFINED'

Plus sign mode

'PROCESSOR_DEFINED'

STATUS (or TYPE)

'OLD'

'NEW'

'SCRATCH'

'REPLACE'

'UNKNOWN'

File status at open

'UNKNOWN'

Note: The default differs under certain conditions (see STATUS Specifier).

TITLE

A scalar default character expression

Title for child window in a QuickWin application

No default

UNIT

A scalar numeric expression

Logical unit number

No default; an io-unit must be specified.

USEROPEN

An external function

User program option

No default

See Also