At 02:52 PM 5/9/95 GMT, Ross Ridge wrote:
>>2) terminate with an _exit() rather than the (implied) exit()
>
>Bad idea.  The implied exit() *is* flushing the stdio buffers, otherwise
....
>If exit() were used instead of _exit() in this example, it could result
>in the message being printed twice, once in the parent process and once
>in the child process.
 
Not knowing exactly what the person's program was doing, the suggestion for
_exit() was more basic.  While what you say will prevent the message from
printing twice, it can prevent it from printing at all.  Where shared
descriptors are present from a vfork(), the exit() function in the child
will not only flush the buffers but close the file too.  As a result, when
the parent process attempts to print to this descriptor it will fail --
closed file.  So instead of only one error message, it may result in none.
 
I've been caught on this on our HP-UX systems before.! :)  I don't know the
status of this on MPE systems.
 
Regards.
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