10个你闻所未闻的Linux命令(十)

 

lsof 列出打开文件，你可以用它做很多很cool的事情，比如查找哪个接口是开放的？

# lsof | grep TCP
portmap 2587 rpc 4u IPv4 5544 TCP *:sunrpc (LISTEN)
rpc.statd 2606 root 6u IPv4 5585 TCP *:668 (LISTEN)
sshd 2788 root 3u IPv6 5991 TCP *:ssh (LISTEN)
sendmail 2843 root 4u IPv4 6160 TCP badhd:smtp (LISTEN)

vsftpd 9337 root 3u IPv4 34949 TCP *:ftp (LISTEN)
cupsd 16459 root 0u IPv4 41061 TCP badhd:ipp (LISTEN)
sshd 16892 root 3u IPv6 61003 TCP badhd.mshome.net:ssh->kontiki.mshome.net:4661 (ESTABLISHED)

Note: OpenBSD 101 pointed out that “lsof -i TCP” a better way to obtain this same information. Thanks!Or find the number of open files a user has. Very important for running big applications like Oracle, DB2, or WebSphere: 

# lsof | grep ' root ' | awk '{print $NF}' | sort | uniq | wc -l
179

提示，匿名评论者指出应该用“sort -u”代替sort | uniq，本人忘记了-u flag，谢谢！