CODEWITHSUNDEEP
linuxbashshelldateksh
maihabunash
maihabunash

Reputation: 1702

How to count time from current reference time

I need to build simple ksh/bash scrip or whatever on Linux t that know to count time from reference time

When I type the date command as the following:

   date

   Wed Jul 17 18:13:27 IDT 2013

or

   [root@linux /var/tmp]# current_time=` date `
   [root@linux /var/tmp]# echo $current_time

                          Wed Jul 17 18:21:51 IDT 2013

So I get here the current date .

What I need is to count for example 10 min from the current date ,

so after 10 min I will print the message

     echo “sorry 10 min was ended“

how to count time from the reference time ?

Upvotes: 2

Views: 580

Answers (2)

chepner
chepner

Reputation: 530872

bash has something like a built-in timer. The parameter $SECONDS is updated continuously with the number of seconds elapsed since the shell was started. You can assign to this variable, in which case its value is essentially incremented each second.

Some examples:

$ SECONDS=0
$ sleep 10
$ echo $SECONDS
10

$ SECONDS=0
$ while (( SECONDS < 600 )); do
>  sleep 10
> done

Upvotes: 4

Yossarian
Yossarian

Reputation: 5471

Use date +%s to get Unix time - the number of seconds since 00:00:00 Coordinated Universal Time (UTC), Thursday, 1 January 1970 - and then use arithmetic expansion:

current_time=$(date +%s)
elapsed_time=$(( $(date +%s) - $current_time ))

$elapsed_time is then the number of seconds since $current_time. You can then check if $elapsed_time > 600 in your loop.

Edit: For completeness:

if [[ $elapsed_time > 600 ]]; then
   echo "sorry 10 min was ended"
fi

This should work in both bash and ksh.

Upvotes: 1

Related Questions