start_stream.sh

#!/bin/bash
 
if pgrep mjpg_streamer > /dev/null
then
  echo "mjpg_streamer already running"
else
  LD_LIBRARY_PATH=/opt/mjpg-streamer/ /opt/mjpg-streamer/mjpg_streamer -i "input_raspicam.so -fps 15 -q 50 -x 640 -y 480 -vf -hf" -o "output_http.so -p 9000 -w /opt/mjpg-streamer/www" > /dev/null 2>&1&
  echo "mjpg_streamer started"
fi

stop_stream.sh

#!/bin/bash
 
if pgrep mjpg_streamer
then
  kill $(pgrep mjpg_streamer) > /dev/null 2>&1
  echo "mjpg_streamer stopped"
else
  echo "mjpg_streamer not running"
fi