写脚本切换用户

1. #!/usr/bin/expect
3. spawn /bin/su
4. expect "Password: "
5. send "u_password\r"
6. expect eof
7. exit

send：用于向进程发送字符串
expect：从进程接收字符串 比如：expect "*assword*"

spawn：启动新的进程
interact：允许用户交互