Question

I have used the & command before to make a script run another script in the background like so:

#!/bin/bash
echo "Hello World"    
script1.sh &
script2.sh &
echo "Please wait..."

But lets say I have another script with an IF ELSE statment and I would like to set an ELIF statement mid flow as a background task with the & and then carry on with processing the rest of my script knowing that while rest of the ELIF will carry running in the back ground:

#!/bin/bash
if cond1; then
   stuff
   sleep 10 &
   stuff
   stuff
elif cond2; then
   something else
else 
   echo "foo"
fi
stuff
echo "Hello World"

I really hope this makes sense any help would be greatly appreciated.

Answer 1

You can run your commands in a subshell. A subshell will execute in a separate (child) process. You can define which commands are ran in a subshell by surrounding them with parentheses.

And, as you know, to run a process in the background just append an &.

---

Here is what your if statement would look like if you were to execute it in a separate, background, process:

#!/bin/bash
( if cond1; then
    stuff
    sleep 10 &
    stuff
    stuff
 elif cond2; then
    something else
 else 
    echo "foo"
 fi
 stuff
 echo "Hello World" ) &