FORTRAN Reference Manual

Introduction to File I/O in the HP NonStop
Environment
FORTRAN Reference Manual—528615-001
5-11
Unit Assignment
The ASSIGN Command
The TACL ASSIGN command enables you to assign the name of an actual file to a unit
specified in a program and to specify the characteristics of the file at run time.
logical-unit
is the unit name specified in the UNITNAME option of the UNIT compiler directive.
The name can be from 1 to 31 characters including letters, digits, and hyphens. If
no UNIT directive specifies the name of a unit, the default unit name has the form
FT uuu, where uuu is a three-digit decimal integer from 1 through 999 which
specifies the unit to be connected: Unit 2 is FT002, unit 99 is FT099, and so forth.
filename
is an HP file name (\ node.$ volume. subvol. fileid). An OPEN statement
can override this value with a FILE specifier.
create-spec
is a specification for one or more of the following file attributes:
exclusion-spec
is the exclusion mode of logical-unit and determines how other
processes can access the file. It is one of the following keywords:
An OPEN statement can override the value of exclusion-spec with a
PROTECT specifier.
ASSIGN [ logical-unit [,[ filename ][, create-spec]... ] ]
Keyword Meaning
EXCLUSIVE No other processes can access the filename while the
program containing logical-unit has the file open.
SHARED Other processes can read and write to filename while the
program containing logical-unit has the file open. This
is the default value.
PROTECTED Other processes can read, but not write to, filename while
the program containing logical-unit has the file open
for write access.