Check if a string contains asterisk (*)

Question

I want to check if my string contains one or more asterisks.

I have tried this:

if [[ $date_alarm =~ .*\*.* ]]
then
    ...
fi

It worked when I launch the script directly, but not if this script is called during shutdown (script installed in run level 0 and 6 via update-rc.d)

Any idea, suggestion?

Answer 1

Always quote strings.

To check if the string $date_alarm contains an asterisk, you can do:

if echo "$date_alarm" | grep '*' > /dev/null; then
    ...
fi

but it's more idiomatic to use a case statement:

case "$date_alarm" in *\**) ...;; esac

Note the quotes. Even thought the quotes really aren't necessary in the case statement (field splitting won't happen there), it is considered best practice to include them.