Guardian Procedure Calls Reference Manual

Table 11 CONTROL Operations 2 Through 27
Description of <param>DescriptionOperation
NoneWrite end of file on unstructured disk or magnetic tape (if disk,
write access is required).
2
A write end of file (EOF) to an unstructured disk file sets EOF
to point to the relative byte address indicated by the next-record
pointer and writes the new EOF setting in the file label on disk.
If this new EOF setting is out of bounds, EOF is set to the last
possible position.
NOTE: CONTROL 2 is valid only for unstructured files or
structured files opened for unstructured access. For XP-based
files, using CONTROL 2 to move the EOF will involve more
CPU cycles. Writing the application data to the file and letting
the disk process move the EOF as the data is written to the
file, and removing the CONTROL 2 operations from the
application code will improve the performance.
NoneMagnetic tape, rewind and unload, do not wait for completion.3
NoneMagnetic tape, take off line, do not wait for completion (treated
as operation 3 for 5106 Tri-Density Tape Drive).
4
Not supported for 5130, 5160, 5170, and 5180 tape drives.
NoneMagnetic tape, rewind leave on line, do not wait for
completion.
5
NoneMagnetic tape, rewind, leave on line, wait for completion.6
number of files {0:255}Magnetic tape, space forward files.7
number of files {0:255}Magnetic tape, space backward files.8
number of records {0:255}Magnetic tape, space forward records.9
number of records {0:255}Magnetic tape, space backward records.10
NoneTerminal or serial-connected line printer, wait for modem
connect.
11
NoneTerminal or serial-connected line printer, disconnect the modem
(that is, hang up).
12
NoneIssue an SNA CHASE request. SNAX exception response mode
must be enabled to use operation 13.
13
NoneTerminal or serial-connected line printer, enable connection
and initiate call to remote DTE in X.25 network.
17
NoneDisk, purge data (write access is required).20
1
This value is supported only on unstructured opens of secondary
partitions of enhanced key-sequenced files.
deallocate all extents past the
end-of-file extent.
0Disk, allocate or deallocate extents (write access is required).21
1
maximum-extents1:
number of extents to allocate for
a nonpartitional file (for DP2 disk
files only).
number of partitions number of
extents to allocate for a
partitioned file.
1:16
1
NoneCancel an AM3270 I/O operation.22
CONTROL Procedure 209