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Markus
Asked: 2014-01-20 05:17:31 +0800 CST

Convert time stamp to seconds in bash

  • 772

As far as I know, bash variables do not have a certain type.

My problem is, I need to convert a time stamp (always in format: hh:mm:ss) to a single integer representing seconds.

So I cut the hh, mm and ss parts into separate strings and use expr to calculate the seconds integer like:

TIME=expr $HH \* 3600 + $MM \* 60 + $SS

But when e.g. $HH=00 then expr won't work. Is it possible to convert strings like 00 or 01 to integers?

bash

3 Answers

  1. Best Answer

    Try awk. For example:

    echo "00:20:40" | awk -F: '{ print ($1 * 3600) + ($2 * 60) + $3 }'

    So, if you have:

    time="00:20:40"

    then:

    seconds=$(echo $time | awk -F: '{ print ($1 * 3600) + ($2 * 60) + $3 }')

    and echo $seconds will print 1240.

    • 7

  2. If you want to convert the current time into second, try this script

    #!/bin/bash

let var=$(date +%H)*3600+$(date +%M)*60+$(date +%S)
echo $var

    It will convert the current time into seconds (an integer).

    If you wish to convert an arbitrary time string like HH:MM:SS into second then it is better to use Radu Rădeanu's answer. I could give something in the way you were trying,

    I am assuming you stored hour, min, and second in HH, MM and SS, then use the following to store time in second into var,

    let var=HH*3600+MM*60+SS
    • 2

  3. If your timestamp is less than 24 hours you can use gnu date and convert to seconds after epoch (January 1st, 1970):

    timestamp="23:59:59" # largest timestamp possible w/ this method
date -d "1970-01-01T${timestamp}" "+%s"

    Output:

    104399
    • 1