pptpd PPP VPN LOG

vpn 服务，但通过last查看的时候，只有登录的IP信息，

tac /var/log/pptpd.log | while read line 
do 
        _tmphead=$(echo $line | cut -d" " -f1,2) 
        _tmptime=$(echo $line | cut -d" " -f3) 
        _tmpuser=$(echo $line | cut -d" " -f5) 
        if [ "IP UP" = "$_tmphead" -a "$PEERNAME" = "$_tmpuser" ] 
        then 
                _rep_line="$line" 
                sed -i "s/$line/$_rep_line\nIP DOWN        \ 
`date -d today +%F_%T`        \ 
$6        \ 
$PEERNAME        \ 
$1        \ 
$5/" /var/log/pptpd.log 
                break 
        fi 
done