Use Local Assign Mode

Details on using local assign mode.

The assign environment information is usually stored in the .assign environment file. Programs that do not require the use of the global .assign environment file can activate local assign mode. If local assign mode is selected, the assign environment will be stored in memory. Thus, other processes can not adversely affect the assign environment used by the program.

The ASNCTL routine selects local assign mode when it is called by using one of the following command lines:

CALL ASNCTL('LOCAL',1,IER)
CALL ASNCTL('NEWLOCAL',1,IER)

Local assign mode

In the following example, a Fortran program activates local assign mode and then specifies an unblocked data file structure for a unit before opening it. The -I option is passed to ASNUNIT to ensure that any assign attributes continue to have an effect at the time of file connection.

C    Switch to local assign environment
     CALL ASNCTL('LOCAL',1,IER)
     IUN = 11
C    Assign the unblocked file structure
     CALL ASNUNIT(IUN,'-I -s unblocked',IER)
C    Open unit 11
     OPEN(IUN,FORM='UNFORMATTED')

If a program contains all necessary assign statements as calls to ASSIGN, ASNUNIT, and ASNFILE, or if a program requires total shielding from any assign commands, use the second form of a call to ASNCTL, as follows:

C    New (empty) local assign environment
     CALL ASNCTL('NEWLOCAL',1,IER)
     IUN = 11
C    Assign a large buffer size
     CALL ASNUNIT(IUN,'-b 336',IER)
C    Open unit 11
     OPEN(IUN,FORM='UNFORMATTED')