Bash Cookbook

How to do it...

Let's start our activity as follows:

1. Open a terminal and create the loop_and_print.sh script:

#!/bin/bash
EXIT_PLEASE=0INC=0until [ ${EXIT_PLEASE} != 0 ] # EXIT_PLEASE is set to 0, until will never be satisfieddo   echo "Boo $INC" > /dev/null   INC=$((INC + 1))   sleep 1doneexit 0

2. Open a terminal and run the following commands:

$ bash loop_and_print.sh &$ ps aux | grep loop_and_print.sh # Take note of the PID - write it down

3. Next, log off, then log in and run the following command in a new terminal:

$ ps aux | grep loop_and_print.sh # Take note of the PID - write it down

4. Can you find the process running? Next, run the following command:

$ bash loop_and_print.sh & # note the PID againg$ disown

5. Next, log off, then log in ...