Ubuntu – How to completely restart script from inside the script itself

#!/bin/bash
# Bash Menu Script Example

PS3='Please enter your choice: '
options=("Option 1" "Option 2" "Option 3" "Quit")
select opt in "${options[@]}"
do
    case $opt in
        "Option 1")
            echo "you chose choice 1"
            ;;
        "Option 2")
            echo "you chose choice 2"
            ;;
        "Option 3")
            echo "you chose choice $REPLY which is $opt"
            ;;
        "Quit")
            break
            ;;
        *) echo "invalid option $REPLY";;
    esac
done

Add break statements wherever you need the select loop to exit. If a break is not performed, the select statement loops and the menu is re-displayed.

In the third option, I included variables that are set by the select statement to demonstrate that you have access to those values. If you choose it, it will output:

you chose choice 3 which is Option 3

You can see that $REPLY contains the string you entered at the prompt. It is used as an index into the array ${options[@]} as if the array were 1 based. The variable $opt contains the string from that index in the array.

Note that the choices could be a simple list directly in the select statement like this:

select opt in foo bar baz 'multi word choice'

but you can't put such a list in a scalar variable because of the spaces in one of the choices.

You can also use file globbing if you are choosing among files:

select file in *.tar.gz

Please, change the line:

pgrep tv-timer | grep -v $$ > ~/tv-timer2.log

into this:

pgrep tv-timer | grep -v ^$$$ > ~/tv-timer2.log

In fact, if one tv-timer prosesses has, say, PID=26019 and should $$ be 6019, then grep would yield an empty string, which is not what you want.