Guardian Procedure Calls Reference Manual

CHECKOPEN Procedure (Superseded by FILE_OPEN_CHKPT_ Procedure)
Summary
Syntax for C Programmers
Syntax for TAL Programmers
Parameters
Condition Code Settings
Considerations
Messages
Summary
NOTE: This procedure is supported for compatibility with previous software and should not be
used for new development.
The CHECKOPEN procedure is called by a primary process to open a designated file for its backup
process. These two conditions must apply before the call to CHECKOPEN:
• The primary process must first open the file.
• The backup process must be in the "monitor" state (that is, in a call to CHECKMONITOR) for
the CHECKOPEN to be successful.
The call to CHECKOPEN causes the CHECKMONITOR procedure in the backup process to call
the file-system FILE_OPEN_ procedure for the designated file.
Syntax for C Programmers
This passive backup procedure is not supported in C programs. For a comparison of active backup
and passive backup, see the Guardian Programmer's Guide.
Syntax for TAL Programmers
CALL CHECKOPEN ( [ file-name ] ! i
,filenum ! i
,[ flags ] ! i
,[ sync-or-receive-depth ] ! i
,[ sequential-block-buffer-id ] ! i
,[ buffer-length ] ! i
,backerror ); ! o
Parameters
With the exception of filenum, all of the input parameters to this procedure are ignored; the
values that were specified when the primary process called OPEN or FILE_OPEN_ are used instead.
The ignored parameters are described under the OPEN procedure.
filenum
output
INT:ref:1
is the number that identifies the file that was opened by the primary process and that is now
to be opened by the backup process.
140 Guardian Procedure Calls (C)