【笔试】诺西 linux shell

【fie operation】Find all .log files which haven't been modified for more than 7 days under /tmp directory and move them to tmp/bak directory, please give the command.

mv `find /tmp -name “*.log” -mtime +7` /tmp/bak

【network】how to capture UDP traffics send/recieved by 10.1.1.1 on port 161, please give the command

tcpdump -i eth0 src host 10.1.1.1 dst host 10.1.1.1 and port 161 and udp

tcpdump -i eth0 -nnA 'port 161 and src host 10.1.1.1 and udp'

which one is right?

【shell】replace all 'abc' as 'xyz' in file a.txt

sed -e `\abc\xyz\g` a.txt

【shell】

$$： shell本身的PID

$! ： shell最后运行的后台process的PID

$? ：上一条命令的返回值

$# ：添加到shell的参数的个数

$-： 使用sed命令设定的flag一览

$*

$@

$0： shell本身的文件名

$1 ~ $n：添加到shell的各个参数值