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.
Some OPEN statement specifiers require a scalar default character expression with a limited set of character values. These values are listed for each specifier. The value specified is without regard to case, and any trailing blanks are ignored.
The following table summarizes details about the OPEN statement specifiers and it contains links to their descriptions:
Specifier |
Values |
Function |
Default |
|---|---|---|---|
'DIRECT' 'SEQUENTIAL' 'STREAM' 'APPEND' |
Access mode |
'SEQUENTIAL' |
|
ACTION (or MODE) |
'READ' 'WRITE' 'READWRITE' |
File access |
'READWRITE' |
A scalar integer variable |
Next direct access record |
No default |
|
'YES' 'NO' |
Asynchronous I/O |
'NO' |
|
'NULL' 'ZERO' |
Interpretation of blanks |
'NULL' |
|
A scalar numeric expression |
Physical I/O transfer size |
131,072 bytes |
|
A scalar numeric expression |
Number of I/O buffers |
One |
|
'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. |
|
'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' |
|
'LITTLE_ENDIAN' 'BIG_ENDIAN' 'CRAY' 'FDX' 'FGX' 'IBM' 'VAXD' 'VAXG' 'NATIVE' |
Numeric format specification |
'NATIVE' |
|
'COMMA' 'POINT' |
Decimal edit mode |
'POINT' |
|
A scalar default character expression |
Default file pathname |
Current working directory |
|
'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' |
'UTF-8' 'DEFAULT' |
Encoding form for a file |
'DEFAULT' |
|
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. |
'FORMATTED' 'UNFORMATTED' 'BINARY' |
Format type |
Depends on ACCESS setting |
|
.TRUE. .FALSE. |
Active window in QuickWin application |
.TRUE. Note: If unit '*' is specified, the default is .FALSE.; otherwise, the default is .TRUE.. |
|
An error message if an error occurs during OPEN. |
Provides error information |
No default |
|
A scalar integer variable |
I/O status |
No default |
|
A scalar numeric expression |
Direct access record limit |
No limit |
|
'PRINT' 'SUPPRESS' 'PROCESSOR_DEFINED' |
Controls printing of optional leading zeros.in formatted numeric output. |
'PROCESSOR_DEFINED' |
|
A scalar integer variable |
Returns automatically chosen, unused, unit number |
No default |
|
No value |
File sharing disallowed |
Linux: SHARED Windows: Not shared |
|
'SEQUENTIAL' 'RELATIVE' |
File organization |
'SEQUENTIAL' |
|
'YES' 'NO' |
Record padding |
'YES' |
|
'ASIS' 'REWIND' 'APPEND' |
File positioning |
'ASIS' |
|
No value |
Write protection |
No default |
|
| (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. |
'FIXED' 'VARIABLE' 'SEGMENTED' 'STREAM' 'STREAM_CR' 'STREAM_LF' |
Record type |
Depends on ORGANIZATION, CARRIAGECONTROL, ACCESS, and FORM settings |
|
'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 |
|
'DENYRW' 'DENYWR' 'DENYRD' 'DENYNONE' |
File locking |
'DENYWR' Note: The default differs under certain conditions (see SHARE Specifier). Other notes:
|
|
No value |
File sharing allowed |
Linux*: SHARED Windows: Not shared |
|
'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). |
A scalar default character expression |
Title for child window in a QuickWin application |
No default |
|
A scalar numeric expression |
Logical unit number |
No default; an io-unit must be specified. |
|
An external function |
User program option |
No default |