Learning Linux Shell Scripting

Running functions in the background

We have already seen in previous chapters that to run any command in the background, we have to terminate the command using &:

$ command &

Similarly, we can make the function run in the background by appending & after the function call. This will make the function run in the background so that the terminal will be free:

#!/bin/bash
dobackup()
{
    echo "Started backup"
    tar -zcvf /dev/st0 /home >/dev/null 2>&1
    echo "Completed backup"
}
dobackup &
echo -n "Task...done."
echo

Test the script as follows:

$ chmod +x function_17.sh
$ ./function_17.sh

Output:

Task...done.
Started backup
Completed backup

Command source and period (.)

Normally, whenever we enter a command, the new process gets created. If we want to make functions ...