Bash if statement with multiple variables

Question

Hello I am trying to make a simple bash script and am very new to it.

With the the if statement I am trying to count up like a clock.

So the output would be for example 16:59:58, 16:59:59, 17:00:00

The seconds and minutes work, however the first if statement is not working.

When it gets to 23:59:59, it is meant to go to 00:00:00 however it goes to 24:60:00

Any help?

if [[ "$hours" -eq 23 && "$minutes" -eq 60 && "$seconds" -eq 60 ]]
then
    seconds=0
    minutes=0
    hours=0
    ((date++))
else
    if [[ "$minutes" -eq 60 ]]
    then
        minutes=00
        ((hours++))
    else
        if [[ "$seconds" -eq 60 ]]
        then
            seconds=00
            ((minutes++))
        fi
    fi
fi

There's also an elif clause available, so that you don't have to nest if statements like this. — chepner
– chepner, Commented Feb 10, 2020 at 16:48
Cool trick, you can write scripts inside (( and if's with ? : ternary operator. (( hours == 23 && minutes == 60 && seconds == 60 && ( seconds = 0, minutes = 0, hours = 0, date++ ) )). to 23:59:59 - then you should compare with 59 not with 60. — KamilCuk
– KamilCuk, Commented Feb 10, 2020 at 16:49
"$hours" -eq 23 should be "$hours" -eq 24. You're testing the value after it has been incremented. — Barmar
– Barmar, Commented Feb 10, 2020 at 16:49
The way you've written it, it will go from 22:59:59 to 0:0:0. — Barmar
– Barmar, Commented Feb 10, 2020 at 16:51

Barmar · Accepted Answer · 2020-02-10 16:55:19Z

1

Work from the lowest order field up, instead of testing all the variables.

((seconds++))
if [[ $seconds -eq 60 ]]
then 
    seconds=0
    ((minutes++))
fi
if [[ $minutes -eq 60 ]]
then
    minutes=0
    ((hours++))
fi
if [[ $hours -eq 24 ]]
then
    hours=0
    ((date++))
fi

answered Feb 10, 2020 at 16:55

Barmar

789k57 gold badges554 silver badges669 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Bash if statement with multiple variables

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related