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To: Danny Braniss <danny@cs.huji.ac.il>
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Cc: freebsd-hackers@freebsd.org
Subject: Re: preventing FIFO from EOF
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Danny Braniss wrote:
>> $ mkfifo /var/tmp/foo
>> $ buffer -i /var/tmp/foo                    # misc/buffer
>> # in another console:
>> $ echo hi > /var/tmp/foo
>>
>> buffer prints hi and exits. I want it to keep reading and printing 
>> indefinitely.
>>
>> Further experimentation revealed that I need two writers: one dummy 
>> writer that just keeps /var/tmp/foo open for writing, and the other 
>> doing the "real work". This way buffer wouldn't exit. But how to emulate 
>> the dummy writer? It itself needs to block on something to keep 
>> /var/tmp/foo open. Any clean way to do this in shell? Maybe the solution 
>> is quite simple but isn't at the tip of my tongue.
>>
>> Thanks.
> 
> too easy
> n csh:
> 	while 1
> 		buffer -i /var/tmp/foo 
> 	end
> or in sh:
> 	while true; do
> 		buffer -i /var/tmp/foo
> 	done
> 

> Thanks, but I should have said that buffer must always run to never miss any data. 

The reason being that buffer's output gets fed into another program that 
shouldn't be restarted.