FORTRAN Reference Manual

Introduction to File I/O in the HP NonStop
Environment
FORTRAN Reference Manual—528615-001
5-12
Unit Assignment
access-spec
is one of the following access modes for logical-unit.
An OPEN statement can override the value of access-spec with the MODE
specifier.
REC record-size
is an integer ranging from 1 through 65,535 which sets the length (in bytes) of
records in logical-unit.
An OPEN statement can override this value with a RECL specifier.
CODE file-code
specifies the file code of the file being connected. 101 specifies an EDIT format
file.
extent-spec
assumes one of the following three forms:
EXT pri-extent
EXT ( pri-extent )
EXT ( [ pri-extent ] , sec-extent )
where pri-extent is an integer in the range from 1 to 65,535 inclusive that
specifies the size of the primary extent, and sec-extent is an integer in the
same range that specifies the size of each secondary extent. Each extent size
is the number of 2048-byte disk pages to be allocated at one time.
BLOCK block-size
is an integer in the range of 1 through 65,535 that specifies the size (in bytes)
of the data blocks used by logical-unit. Although you can specify the
block size, the FORTRAN (and COBOL85) run-time environments do not use
the value you specify.
For example, the following TACL ASSIGN command assigns the file name DATAFILE
to unit 2:
1> ASSIGN FT002, datafile, input, exclusive
To get a list of the attributes of a logical file, enter:
1> ASSIGN logical-unit
Keyword Meaning
I-O This process can both read from and write to the file. I-O is
the default value.
INPUT This process can only read the file.
OUTPUT This process can only write to the file.