如何尾随w命令

Question

is there a way to track who has logged in or out in real time. At the moment I run w but it exits as soon as it is done. I am thinking there might be some way to tail the w command or run it continuously.

Answer 1

您可以尝试以下命令：

watch -n1 w

Answer 2

login/logout info is stored at /var/log/wtmp* also ( http://linux.about.com/library/cmd/blcmdl5_wtmp.htm )

you can get those info by watch last

Answer 3

You could run it in a infinite while loop, and throw off prompts whenever a new user enters.

#!/usr/bin/bash
b=`w|cut -d' ' -f1`;
while (true)
    do
        a=`w|cut -d' ' -f1`;
        if [ "$b" != "$a" ]
            then
            echo "new user!";
        fi
        b=$a;
    sleep 1;
    done