Bash processes

example

 1 #!/bin/bash
 2 
 3 count() {
 4         NAME=$1
 5         COUNT_TO=$2
 6         COUNTER=0
 7         echo -e "My name is $NAME my PID is $BASHPID" # $$ does not show subshell PID
 8         while test $COUNTER -le $COUNT_TO
 9         do
10                 sleep 1
11                 let COUNTER=COUNTER+1
12                 echo -e "$NAME countet to $COUNTER"
13         done
14         echo -e "$NAME signing off"
15 }
16 
17 #Main
18 echo -e "I am the main function and my PID is $BASHPID"
19 
20 count "Hans" 5 &
21 count "Ulla" 3 &
22 
23 wait # Wait for subshells to finish
24 echo -e "Main thread signing off"

Gives the following output

My name is Hans my PID is 813980
My name is Ulla my PID is 813981
Hans countet to 1
Ulla countet to 1
Ulla countet to 2
Hans countet to 2
Ulla countet to 3
Hans countet to 3
Hans countet to 4
Ulla countet to 4
Ulla signing off
Hans countet to 5
Hans countet to 6
Hans signing off
Main thread signing off