Greetings.

While my honorable brethren are of course totally right, I'd also like to point out that for the sole purpose of getting the example to work according to your expectations you might take advantage of the line buffering behavior of standard output and just print your stuff in one line. Then turn off buffering/change output device and everything goes southwest again.

The moral is that if you want serial access to a shared resource - this is the general problem you are after - you either:

• Know darn well that what you are doing is guaranteed to be atomic - much documentation reading usually required.

  OR

• Create a resource manager process along with a protocol to talk to it (the suggestion about piping amounts to this)

  OR

• Lock the resource for the time you are acceding it - look at flock and system V semaphores. Then start worrying about deadlocks, startvation and other crazy stuff :)

Cheers,
alf