linux - How to count time from current reference time -

i need build simple ksh/bash scrip or whatever on linux t know count time reference time

when type date command following:

   date     wed jul 17 18:13:27 idt 2013

   [root@linux /var/tmp]# current_time=` date `    [root@linux /var/tmp]# echo $current_time                            wed jul 17 18:21:51 idt 2013

so here current date .

what need count example 10 min current date ,

so after 10 min print message

     echo “sorry 10 min ended“

how count time reference time ?

use date +%s unix time - number of seconds since 00:00:00 coordinated universal time (utc), thursday, 1 january 1970 - , use arithmetic expansion:

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

$elapsed_time number of seconds since $current_time. can check if $elapsed_time > 600 in loop.

edit: completeness:

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

this should work in both bash , ksh.

Live