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Ask the Wizard Questions

C Language: Output rate

The Question is:

    How do I control the output rate of a detached
    process writing to sys$output?. SET OUTPUT_RATE
    only works on the DCL level, right ?
    However my program is written in C. I've tried using
    fsync() and things like that but apparently it has
    no effect when used on sys$output. Whatever I try
    the output rate is still one minute !!


The Answer is:


:    How do I control the output rate of a detached
:    process writing to sys$output?.

   By writing the information at the prefered interval.  As you
   state you are using a detached process, you have full control over
   when and how the application writes its output.

:   SET OUTPUT_RATE only works on the DCL level, right ?
:    However my program is written in C. I've tried using
:    fsync() and things like that but apparently it has
:    no effect when used on sys$output. Whatever I try
:    the output rate is still one minute !!

    fflush is likely of interest here.

    SET OUTPUT will be of interest if -- and only if -- the detached
    process is running under DCL.  (If LOGINOUT was not directly or
    indirectly invoked in the context of the detached process, it is
    not running DCL.)

    If one wishes to maintain a log file from within a detached process,
    it is common practice for the detached process to explicitly open
    the output file.  The application thus has full control over the
    contents of the log file, and how the log file is processed.  This
    also allows the application to explicitly choose file sharing
    options.

    Note that a STOP/ID, $delprc, or similar can result in the last few
    I/O buffers not being written to the log file.  If behaviour this is
    of concern, a call to $forcex is recommended.