OPEN Statement Overview

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 the OPEN statement specifiers and their values (and contains links to their descriptions):

OPEN Statement Specifiers and Values

Specifier

Values

Function

Default

ACCESS

'SEQUENTIAL'

'DIRECT'

'APPEND'

Access mode

'SEQUENTIAL'

ACTION

(or MODE)

'READ'

'WRITE'

'READWRITE'

File access

'READWRITE'

ASSOCIATEVARIABLE

var

Next direct access record

No default

BLANK

'NULL'

'ZERO'

Interpretation of blanks

'NULL'

BLOCKSIZE

n_expr

Physical block size

Filesystem default

BUFFERCOUNT

n_expr

Number of I/O buffers

One

BUFFERED

'YES'

'NO'

Buffering for WRITE operations

'NO'

CARRIAGECONTROL

'FORTRAN'

'LIST'

'NONE'

Print control

Formatted: 'LIST'1

Unformatted: 'NONE'

CONVERT

'LITTLE_ENDIAN'

'BIG_ENDIAN'

'CRAY'

'FDX'

'FGX'

'IBM'

'VAXD'

'VAXG'

'NATIVE'

Numeric format specification

'NATIVE'

DEFAULTFILE

c_expr

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'

ERR

label

Error transfer control

No default

FILE (or NAME)

c_expr

File pathname (file name)

fort.n 2

FORM

'FORMATTED'

'UNFORMATTED'

'BINARY'

Format type

Depends on ACCESS setting

IOFOCUS

.TRUE.

.FALSE.

Active window in QuickWin application

.TRUE.3

IOSTAT

var

I/O status

No default

MAXREC

n_expr

Direct access record limit

No limit

NOSHARED 4

No value

File sharing disallowed

L*X, M*X: SHARED

W*32, W*64: 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)

n_expr

Record length

Depends on RECORDTYPE, ORGANIZATION, and FORM settings 5

RECORDTYPE

'FIXED'

'VARIABLE'

'SEGMENTED'

'STREAM'

'STREAM_CR'

'STREAM_LF'

Record type

Depends on ORGANIZATION, CARRIAGECONTROL, ACCESS, and FORM settings

SHARE 4

'DENYRW'

'DENYWR'6

'DENYRD'6

'DENYNONE'

File locking

'DENYWR' 7

SHARED 4

No value

File sharing allowed

L*X, M*X: SHARED

W*32, W*64: Not shared

STATUS (or TYPE)

'OLD'

'NEW'

'SCRATCH'

'REPLACE'

'UNKNOWN'

File status at open

'UNKNOWN' 8

TITLE

c_expr

Title for child window in QuickWin application

No default

UNIT

n_expr

Logical unit number

No default; an io-unit must be specified

USEROPEN

func

User program option

No default

1 If you use the compiler option specifying OpenVMS defaults, and the unit is connected to a terminal, the default is 'FORTRAN'.

2 n is the unit number.

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

4 For information on file sharing, see Building Applications.

5 On Linux* and Mac OS* X systems, the default depends only on the FORM setting.

6 W*32, W*64

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

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

Key to Values

c_expr: A scalar default character expression

func: An external function

label: A statement label

n_expr: A scalar numeric expression

var: A scalar integer variable

See Also