쉘스크립트 샘플..

last test-user | count_time.sh > test.txt

그러면 결과가

total login time = 01:24

이렇게 나오네요.

count_time.sh

#!/bin/sh

total_login_hour=0
total_login_minute=0

while read user tty ip weekday month date start_time dash end_time login_time; do
    login_hour=${login_time:1:2}
    login_minute=${login_time:4:2}

    let total_login_hour+=login_hour
    let total_login_minute+=login_minute
done

let total_login_hour+=total_login_minute/60
let total_login_minute%=60

printf "total login time = %02d:%02d\n" $total_login_hour $total_login_minute