Check SMART status on MacOS and pop up alert

Question

So I don't know much about bash scripting. I am just a beginner. I made this script which checks the SMART status of my root volume and if it is failing then it immediately throws a pop up alert if my drive is failing. Here's the code:

A=$( diskutil info disk0 | grep SMART )
if [ "$A" != " SMART Status: Verified" ]
then
osascript -e 'tell application "Finder" to activate' -e 'tell 
application "Finder" to display dialog "Your Drive is failing, 
Please backup all your important files now" buttons 
{"OK"} with icon stop'
fi

I know this is so simple. Do you have any suggestions to improve it?

Answer 1

Some suggestions:

• A direct string comparison test may be flaky especially if the string contains multiple space characters. I can think of three alternatives:

  • Use regex matching: this can be achieved by the =~ operator inside [[ ]]: if [[ ! "$A" =~ Verified ]].

  • Use awk:

    A=$(diskutil info disk0 | awk '/SMART Status:/{print $NF}')
    if [ "$A" != 'Verified' ]
    # ...
    

  • Check exit status instead of output:

    if sudo smartctl -H -q silent /dev/disk0
    # ...
    

• Use more descriptive names: smart_status_text is more self-evident than A.

• Properly format your code: indent the commands inside the if block and don't leave a blank line after then.