Shell Programming and Scripting

grep $user /tmp/$USER.wtmp| sort  -k 7rn,7 -k 4rM,4 -k 5rn,5 -k 6rn,6  | while read  uname tty st_dow st_mon st_day st_time st_yr junk end_dow end_mon end_day end_time end_yr ttime host 
do
    case $end_dow in
        crash|gone|down|still) ;;       # ignore those with missing info
        *)
            printf "\n"
            printf "       User:\t%s\n" $uname
            printf "      Start:\t%s %s %s %s\n" $st_dow $st_mon $st_day $st_time
            printf "        End:\t%s %s %s %s\n" $end_dow $end_mon $end_day $end_time
            printf "    Time On:\t%s\n" $ttime
            printf "Remote Host:\t%s\n" ${host:-localhost}
            exit 0
        ;;
    esac
done

leng=`expr length "$username"`
# if username length is more than 8 characters print an error.
if [ $leng -gt 8 ]; then
    new_username=$(echo $username | cut -c 1-8)
    else
    new_username=$username
fi
ls /var/log/wtmp*bz2 | while read file    # for each wtmp file
do
    bunzip2 -dc $file >$tfile    # uncompress writing output to tmp file
    last -F -a -f $tfile         # run last on it
    done >$big_file             # save all output from last in one file

last -F -a >>$big_file              # append formatted output from current wtmp

rm $tfile                           # tmp file not needed

echo $big_file | egrep $new_username /tmp/tst/$USER.wtmp > /tmp/tst/mytst

# The Start Date Calculation
st_dat=$(cat /tmp/tst/mytst | head -1 | cut -c 27-32)
st_dat1=$(cat /tmp/tst/mytst | head -1 | cut -c 43-46)
st_dat2=$(echo $st_dat", "$st_dat1)
echo Start Date:    $st_dat2    # THIS IS THE START DATE OUTPUT
# The End Date Calculation
end_dat=$(cat /tmp/tst/mytst | tail -1 | cut -c 53-59)
end_dat1=$(cat /tmp/tst/mytst | tail -1| cut -c 70-75 )
end_dat2=$(echo $end_dat", "$end_dat1)
echo End Date:    $end_dat2    # THIS IS THE START DATE OUTPUT

myusername pts/0 Thu Jun 9 13:38:50 2011 - Thu Jun 9 14:50:32 2011 (01:11) 142.204.248.97

st_dat1=$(head -1 cat /tmp/tst/mytst | cut -c 43-46)

st_dat2="$st_dat, $st_dat1"