6100 ADCCP Programming Manual

Application Tasks
Writing Applications that Use ADCCP
069225 Tandem Computers Incorporated 4–5
OPEN Procedure
A call to the OPEN procedure obtains access to the specified communications line.
When OPEN finishes, a file number returns to the application process. The file
number identifies access to this communications line in subsequent file-system calls.
If an application uses multiple OPEN calls, it can issue separate AWAITIO calls to
complete each set of requests, or it may issue one AWAITIO call with a -1 instead of
the file number. If a request finishes with a nonzero condition code, the FILEINFO call
should use the file number returned by AWAITIO.
CALL OPEN ( file-name !i
, filenum !o
, [ flags ] !i
, [ sync-depth ] ) !i
file-name input
INT:ref:12
is an array that contains the device name assigned to the particular
communications line at system generation time.
filenum output
INT:ref:1
returns a file number that uniquely identifies this particular opening of the
specified line. All subsequent procedure calls associated with this particular line
identified by filenum refer to the line by this file number. A -1 is returned if OPEN
fails.
flags input
INT:value
indicates the type of access to the line and the number of outstanding I/O
operations. The following table shows the bits used in this bit flag for an ADCCP
line.
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