Write to STDIN of running Process

write-stdin.sh

## Alternative 1: write to file descriptor (not usable)
input='testing'
pid=1212

echo $input > /proc/$pid/fd/0

## Alternative 2: Pipe fifo to the app

fifo_file=/tmp/fifo

mkfifo $fifo_file; cat > $fifo_file &; echo $! > {$fifo_file}.pid
(cat $fifo_file | myapp)

echo "testing" > $fifo_file

kill -9 `cat $fifo_file.pid` && rm $fifo_file*