bash while loop compound check

Question

New to bash here. Trying to write a while loop that checks for 3 conditions, 2 user input and if a ping command failed. How to combine all 3 into 1 big statement? Would like to check that user didn't enter Y or y or ping to google.com failed

attempt:

# Ask user to confirm ethernet cable connected or quit with Yy or Qq in continous loop.
echo -e "Connect ethernet cable to Pi Slave. Type (Y) when done, (Q) to quit:" 
read confirm
# If confirm is Y or y, continue to rest of script
while [[ "$confirm" != "Y" && "$confirm" != "y" && ping -q -c 1 -w 1 google.com  ]]
do
    if [[ "$confirm" == "Q" || "$confirm" == "q" ]]; then
        exit 1
    fi
    echo -e "Connect ethernet cable to Pi Master. Type (Y) when done, (Q) to quit:" 
    read confirm
done

John Kugelman · Accepted Answer · 2018-09-26 03:21:39Z

3

[[ ... ]] only accepts simple tests. Full commands like ping stand on their own.

while [[ "$confirm" != "Y" && "$confirm" != "y" ]] && ! ping -q -c 1 -w 1 google.com

To get rid of the duplicate prompt code you could rewrite the loop as:

while true; do
    read -p "Connect ethernet cable to Pi Slave. Type (Y) when done, (Q) to quit: " confirm

    case $confirm in
        [yY]) ping -q -c 1 -w 1 google.com && break;;
        [qQ]) exit 1;;
        *)    continue;;
    esac
done

edited Sep 26, 2018 at 3:21

answered Sep 26, 2018 at 3:15

John Kugelman

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1 Comment

Lightsout Over a year ago

I like that explaination that [[ ]] is a command. How come you edit it out?

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