Hi Tim
Happy New Year to you too.
This is expected behaviour with pipes. The first process to open the pipe will
block until the other end opens too.
You confirm with the following - the first echo does not happen until the shell
itself has completed the open (</tmp/pipe)
time { echo hello ; read -t 1 ;} </tmp/pipe
You can try something like this and drop it in the background before the read
sleep 999 >/tmp/pipe &
Cheers,
Fred
On 07/01/2021 09:31, Tim Woodall via GLLUG wrote:
Happy new year to all.
I didn't expect this:
tim@einstein(9):~$ mkfifo /tmp/pipe
tim@einstein(9):~$ time read -t 1 </tmp/pipe
real 0m13.514s
user 0m0.000s
sys 0m0.000s
tim@einstein(9):~$
in another terminal I did:
tim@einstein(10):~$ echo >/tmp/pipe
I had expected the read to time out after one second.
Is there any way to make read always timeout, even if the other end of
the pipe isn't connected?
Tim.
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