Guardian Procedure Calls Reference Manual

• Nowait I/O initiated with these routines may be canceled with a call to CANCEL or
CANCELREQ. The I/O is canceled if the file is closed before the I/O completes or AWAITIOX
is called with a positive time limit and specific file number and the request times out.
• If the extended address of the buffer is odd, bounds checking rounds the address to the next
lower word boundary and checks an extra byte as well. The odd address is used for the
transfer.
Errors for WRITEUPDATEX Only
In addition to the errors returned from the WRITEUPDATE procedure, file-system error 22 is returned
when:
• The segment is in use at the time of the call or the segment in use is invalid.
• The address of a parameter is extended, but it is an absolute address and the caller is not
privileged.
• The file system cannot use the user's segment when needed.
Example
In the following example, the application makes the necessary changes to the record in TAPE^BUF,
then edits the tape by calling WRITEUPDATE. The tape is backspaced over the record just read,
then updated by writing the new record in its place. NUM^READ indicates the number of bytes
to be written (ensuring that the same number of bytes just read are also written).
CALL WRITEUPDATE ( TAPE^NUM , TAPE^BUF , NUM^READ , NUM^WRITTEN );
Related Programming Manuals
For programming information about the WRITEUPDATE procedure, see the Enscribe Programmer's
Guide and the Guardian Programmer's Guide.
WRITEUPDATE[X] Procedures 1515