每天一个linux命令（lsof）

losf----系统级监控、诊断工具

安装：yum install lsof

格式：lsof [选项] [绝对路径文件名 | 其他参数]

主要选项：

+D：递归查找除该路径下所有打开的文件

[root@root ~]# lsof +D /usr/lib
COMMAND    PID    USER  FD   TYPE DEVICE  SIZE/OFF    NODE NAME
systemd      1    root txt    REG  253,1   1482272  661006 /usr/lib/systemd/systemd
systemd-j  328    root txt    REG  253,1    274768  661020 /usr/lib/systemd/systemd-journald
systemd-u  349    root txt    REG  253,1    361376  661038 /usr/lib/systemd/systemd-udevd
systemd-u  349    root mem    REG  253,1    432831 1048900 /usr/lib/modules/3.10.0-514.26.2.el7.x86_64/modules.symbols.bin
systemd-u  349    root mem    REG  253,1    735054 1048897 /usr/lib/modules/3.10.0-514.26.2.el7.x86_64/modules.alias.bin
systemd-u  349    root mem    REG  253,1    343333 1048848 /usr/lib/modules/3.10.0-514.26.2.el7.x86_64/modules.dep.bin
systemd-u  349    root mem    REG  253,1      8035 1048901 /usr/lib/modules/3.10.0-514.26.2.el7.x86_64/modules.builtin.bin
polkitd    440 polkitd txt    REG  253,1    120424  788678 /usr/lib/polkit-1/polkitd
systemd-l  461    root txt    REG  253,1    572288  661022 /usr/lib/systemd/systemd-logind
crond      463    root mem    REG  253,1 106070960  662766 /usr/lib/locale/locale-archive
agetty     477    root mem    REG  253,1 106070960  662766 /usr/lib/locale/locale-archive
agetty     478    root mem    REG  253,1 106070960  662766 /usr/lib/locale/locale-archive
tuned      746    root mem    REG  253,1 106070960  662766 /usr/lib/locale/locale-archive
bash      4192    root mem    REG  253,1 106070960  662766 /usr/lib/locale/locale-archive
lsof      4274    root mem    REG  253,1 106070960  662766 /usr/lib/locale/locale-archive
lsof      4275    root mem    REG  253,1 106070960  662766 /usr/lib/locale/locale-archive

-u：列出某个用户打开的所有文件，可以指定多个用户

[root@root ~]# lsof -u root -u polkitd
COMMAND     PID    USER   FD      TYPE             DEVICE  SIZE/OFF       NODE NAME
systemd       1    root  cwd       DIR              253,1      4096          2 /
systemd       1    root  rtd       DIR              253,1      4096          2 /
systemd       1    root  txt       REG              253,1   1482272     661006 /usr/lib/systemd/systemd
systemd       1    root  mem       REG              253,1     20040     657574 /usr/lib64/libuuid.so.1.3.0
systemd       1    root  mem       REG              253,1    256960     659353 /usr/lib64/libblkid.so.1.1.0
vballoon    383    root  txt   unknown                                         /proc/383/exe
polkitd     440 polkitd  cwd       DIR              253,1      4096          2 /
polkitd     440 polkitd  rtd       DIR              253,1      4096          2 /
polkitd     440 polkitd  txt       REG              253,1    120424     788678 /usr/lib/polkit-1/polkitd
polkitd     440 polkitd  mem       REG              253,1     62184     657115 /usr/lib64/libnss_files-2.17.so
polkitd     440 polkitd  mem       REG              253,1     68192     657657 /usr/lib64/libbz2.so.1.0.6
polkitd     440 polkitd  mem       REG              253,1     99952     657624 /usr/lib64/libelf-0.166.so
polkitd     440 polkitd  mem       REG              253,1     19888     657701 /usr/lib64/libattr.so.1.1.0
polkitd     440 polkitd  mem       REG              253,1    398264     657523 /usr/lib64/libpcre.so.1.2.0
polkitd     440 polkitd  mem       REG              253,1    999944     657405 /usr/lib64/libstdc++.so.6.0.19
polkitd     440 polkitd  mem       REG              253,1    251784     662792 /usr/lib64/libnspr4.so
………

-c：查找某个程序打开的文件比如apache，可以指定多个-c参数使用空格隔开

[root@root ~]# lsof -c ssh
COMMAND  PID USER   FD   TYPE             DEVICE SIZE/OFF   NODE NAME
sshd    3158 root  cwd    DIR              253,1     4096      2 /
sshd    3158 root  rtd    DIR              253,1     4096      2 /
sshd    3158 root  txt    REG              253,1   823744 662215 /usr/sbin/sshd
sshd    3158 root  mem    REG              253,1    62184 657115 /usr/lib64/libnss_files-2.17.so
sshd    3158 root  mem    REG              253,1    68192 657657 /usr/lib64/libbz2.so.1.0.6
sshd    3158 root  mem    REG              253,1    99952 657624 /usr/lib64/libelf-0.166.so
sshd    3158 root  mem    REG              253,1    19888 657701 /usr/lib64/libattr.so.1.1.0
sshd    3158 root  mem    REG              253,1    15688 658041 /usr/lib64/libkeyutils.so.1.5
………

^：执行取反操作比如lsof –u ^root  列出除root用户外的所有用户打开的文件

-p：列出由某个PID对应的进程打开的文件，也就是通过进程id进行过滤输出可以指定多个pid，使用逗号隔开

[root@root ~]# lsof -p 3158
COMMAND  PID USER   FD   TYPE             DEVICE SIZE/OFF   NODE NAME
sshd    3158 root  cwd    DIR              253,1     4096      2 /
sshd    3158 root  rtd    DIR              253,1     4096      2 /
sshd    3158 root  txt    REG              253,1   823744 662215 /usr/sbin/sshd
sshd    3158 root  mem    REG              253,1    62184 657115 /usr/lib64/libnss_files-2.17.so
sshd    3158 root  mem    REG              253,1    68192 657657 /usr/lib64/libbz2.so.1.0.6
sshd    3158 root  mem    REG              253,1    99952 657624 /usr/lib64/libelf-0.166.so
sshd    3158 root  mem    REG              253,1    19888 657701 /usr/lib64/libattr.so.1.1.0
………

-i：列出所有网络连接，可以添加参数比如tcp、udp以及端口

[root@root ~]# lsof -i tcp
COMMAND     PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
sshd       3158 root    3u  IPv4  16225      0t0  TCP *:ssh (LISTEN)
sshd       4190 root    3u  IPv4 221839      0t0  TCP root:ssh->116.23.154.188:55184 (ESTABLISHED)
AliYunDun 18754 root   20u  IPv4  36643      0t0  TCP root:42866->100.100.30.25:http (ESTABLISHED)[root@root ~]# lsof -i :22COMMAND  PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAMEsshd    3158 root    3u  IPv4  16225      0t0  TCP *:ssh (LISTEN)sshd    4190 root    3u  IPv4 221839      0t0  TCP root:ssh->116.23.154.188:55184 (ESTABLISHED)--组合使用[root@root ~]# lsof -i tcp:55184COMMAND  PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAMEsshd    4190 root    3u  IPv4 221839      0t0  TCP root:ssh->116.23.154.188:55184 (ESTABLISHED)

-N：列出所有NFS（网络文件系统）文件

-t：输出进程的pid常与-i组合使用

[root@root ~]# lsof -t -i tcp
3158
4190
18754

-r：用于循环列出文件直到被中断，比如用来检测网络活动，-r后面的 1 表示每秒重复打印一次

[root@root ~]# lsof -r 1 -u root -i -a
COMMAND     PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
dhclient    685 root    6u  IPv4  12108      0t0  UDP *:bootpc
dhclient    685 root   20u  IPv4  12072      0t0  UDP *:17859
dhclient    685 root   21u  IPv6  12073      0t0  UDP *:46450
sshd       3158 root    3u  IPv4  16225      0t0  TCP *:ssh (LISTEN)
sshd       4190 root    3u  IPv4 221839      0t0  TCP root:ssh->116.23.154.188:55184 (ESTABLISHED)
AliYunDun 18754 root   20u  IPv4  36643      0t0  TCP root:42866->100.100.30.25:http (ESTABLISHED)
=======
COMMAND     PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
dhclient    685 root    6u  IPv4  12108      0t0  UDP *:bootpc
dhclient    685 root   20u  IPv4  12072      0t0  UDP *:17859
dhclient    685 root   21u  IPv6  12073      0t0  UDP *:46450
sshd       3158 root    3u  IPv4  16225      0t0  TCP *:ssh (LISTEN)
sshd       4190 root    3u  IPv4 221839      0t0  TCP root:ssh->116.23.154.188:55184 (ESTABLISHED)
AliYunDun 18754 root   20u  IPv4  36643      0t0  TCP root:42866->100.100.30.25:http (ESTABLISHED)

-a：可以将多个选项组合条件由“或”变为“与”

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