Linux Shell Scripting Cookbook - Third Edition

How to do it...

This script will determine the active users and generate the report:

 #!/bin/bash #Filename: active_users.sh #Description: Reporting tool to find out active users log=/var/log/wtmp if [[ -n $1 ]]; then log=$1 fi printf "%-4s %-10s %-10s %-6s %-8s\n" "Rank" "User" "Start" \ "Logins" "Usage hours" last -f $log | head -n -2 > /tmp/ulog.$$ cat /tmp/ulog.$$ | cut -d' ' -f1 | sort | uniq> /tmp/users.$$ ( while read user; do grep ^$user /tmp/ulog.$$ > /tmp/user.$$ minutes=0 while read t do s=$(echo $t | awk -F: '{ print ($1 * 60) + $2 }') let minutes=minutes+s done< <(cat /tmp/user.$$ | awk '{ print $NF }' | tr -d ')(') firstlog=$(tail -n 1 /tmp/user.$$ | awk '{ print $5,$6 }') nlogins=$(cat /tmp/user.$$ | wc -l) hours=$(echo "$minutes ...