Pipes are not read after they are exhausted

[eplodn]

We need to periodically run some command and add the output to the plot.

session-1 $ mkfifo /tmp/fifo
session-1 $ echo "i\tx\ty" >> /tmp/fifo
session-1 $ echo "1\t0\t3" >> /tmp/fifo
session-1 $ echo "2\t1\t4" >> /tmp/fifo
...

session-2 $ ./termeter < /tmp/fifo
# termeter starts and plots the data

session-1 $ echo "10\t33\t44" >> /tmp/fifo
# this data does not get plotted since fifo is exhausted by the start of termeter

Workaround is sending the output to a temp file and starting termeter with tail -f tempfile; it would be great if we could do it without using tail.