Linux查看端口号ss和losf指令
SS指令
ss是Socket Statistics的缩写。顾名思义，ss命令可以用来获取socket统计信息，它可以显示和netstat类似的内容。ss的优势在于它能够显示更多更详细的有关TCP和连接状态的信息，而且比netstat更快速更高效。
1- 全部命令参数
Usage: ss [ OPTIONS ] ss [ OPTIONS ] [ FILTER ] -h, --help this message -V, --version output version information -n, --numeric don't resolve service names -r, --resolve resolve host names -a, --all display all sockets -l, --listening display listening sockets -o, --options show timer information -e, --extended show detailed socket information -m, --memory show socket memory usage -p, --processes show process using socket -i, --info show internal TCP information -s, --summary show socket usage summary -b, --bpf show bpf filter socket information -E, --events continually display sockets as they are destroyed -Z, --context display process SELinux security contexts -z, --contexts display process and socket SELinux security contexts -N, --net switch to the specified network namespace name -4, --ipv4 display only IP version 4 sockets -6, --ipv6 display only IP version 6 sockets -0, --packet display PACKET sockets -t, --tcp display only TCP sockets -S, --sctp display only SCTP sockets -u, --udp display only UDP sockets -d, --dccp display only DCCP sockets -w, --raw display only RAW sockets -x, --unix display only Unix domain sockets --vsock display only vsock sockets -f, --family=FAMILY display sockets of type FAMILY FAMILY := {inet|inet6|link|unix|netlink|vsock|help} -K, --kill forcibly close sockets, display what was closed -H, --no-header Suppress header line -A, --query=QUERY, --socket=QUERY QUERY := {all|inet|tcp|udp|raw|unix|unix_dgram|unix_stream|unix_seqpacket|packet|netlink|vsock_stream|vsock_dgram}[,QUERY] -D, --diag=FILE Dump raw information about TCP sockets to FILE -F, --filter=FILE read filter information from FILE FILTER := [ state STATE-FILTER ] [ EXPRESSION ] STATE-FILTER := {all|connected|synchronized|bucket|big|TCP-STATES} TCP-STATES := {established|syn-sent|syn-recv|fin-wait-{1,2}|time-wait|closed|close-wait|last-ack|listen|closing} connected := {established|syn-sent|syn-recv|fin-wait-{1,2}|time-wait|close-wait|last-ack|closing} synchronized := {established|syn-recv|fin-wait-{1,2}|time-wait|close-wait|last-ack|closing} bucket := {syn-recv|time-wait} big := {established|syn-sent|fin-wait-{1,2}|closed|close-wait|last-ack|listen|closing}
2-常用命令参数
-n, --numeric don't resolve service names -r, --resolve resolve host names -a, --all display all sockets -l, --listening display listening sockets -s, --summary show socket usage summary -p, --processes show process using socket -t, --tcp display only TCP sockets
3-示例：ss -lntps | grep 22； 查看被监听的TCP socket，不解析服务名称，并展示使用概要
[root@izbp10ebr6tsvo83iahgzdz ~]# ss -lntps | grep 22 LISTEN 0 128 *:22 *:* users:(("sshd",pid=5376,fd=3)) LISTEN 0 50 *:39171 *:* users:(("java",pid=5622,fd=84)) LISTEN 0 50 192.168.0.162:9092 *:* users:(("java",pid=5622,fd=100))
losf指令
lsof(list open files)是一个查看进程打开的文件的工具。
在 linux 系统中，一切皆文件。通过文件不仅仅可以访问常规数据，还可以访问网络连接和硬件。所以 lsof 命令不仅可以查看进程打开的文件、目录，还可以查看进程监听的端口等 socket 相关的信息。本文将介绍 lsof 命令的基本用法，本文中 demo 的演示环境为 ubuntu 18.04。
1-全部指令
usage: [-?abhKlnNoOPRtUvVX] [+|-c c] [+|-d s] [+D D] [+|-f[gG]] [+|-e s] [-F [f]] [-g [s]] [-i [i]] [+|-L [l]] [+m [m]] [+|-M] [-o [o]] [-p s] [+|-r [t]] [-s [p:s]] [-S [t]] [-T [t]] [-u s] [+|-w] [-x [fl]] [--] [names] Defaults in parentheses; comma-separated set (s) items; dash-separated ranges. -?|-h list help -a AND selections (OR) -b avoid kernel blocks -c c cmd c ^c /c/[bix] +c w COMMAND width (9) +d s dir s files -d s select by FD set +D D dir D tree *SLOW?* +|-e s exempt s *RISKY* -i select IPv[46] files -K list tasKs (threads) -l list UID numbers -n no host names -N select NFS files -o list file offset -O no overhead *RISKY* -P no port names -R list paRent PID -s list file size -t terse listing -T disable TCP/TPI info -U select Unix socket -v list version info -V verbose search +|-w Warnings (+) -X skip TCP&UDP* files -Z Z context [Z] -- end option scan +f|-f +filesystem or -file names +|-f[gG] flaGs -F [f] select fields; -F? for help +|-L [l] list (+) suppress (-) link counts < l (0 = all; default = 0) +m [m] use|create mount supplement +|-M portMap registration (-) -o o o 0t offset digits (8) -p s exclude(^)|select PIDs -S [t] t second stat timeout (15) -T qs TCP/TPI Q,St (s) info -g [s] exclude(^)|select and print process group IDs -i i select by IPv[46] address: [46][proto][@host|addr][:svc_list|port_list] +|-r [t[m<fmt>]] repeat every t seconds (15); + until no files, - forever. An optional suffix to t is m<fmt>; m must separate t from <fmt> and <fmt> is an strftime(3) format for the marker line. -s p:s exclude(^)|select protocol (p = TCP|UDP) states by name(s). -u s exclude(^)|select login|UID set s -x [fl] cross over +d|+D File systems or symbolic Links names select named files or files on named file systems Anyone can list all files; /dev warnings disabled; kernel ID check disabled.
2- 示例lsof -i:80； 查看80端口号使用情况
[root@izbp10ebr6tsvo83iahgzdz ~]# lsof -i:80 COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME AliYunDun 1361 root 23u IPv4 138060354 0t0 TCP izbp10ebr6tsvo83iahgzdz:57616->100.100.30.25:http (ESTABLISHED) java 26371 root 52u IPv4 148249126 0t0 TCP *:http (LISTEN) java 26371 root 82u IPv4 148614502 0t0 TCP izbp10ebr6tsvo83iahgzdz:36182->223.71.183.165:http (CLOSE_WAIT) java 26371 root 87u IPv4 149877148 0t0 TCP izbp10ebr6tsvo83iahgzdz:34042->223.71.183.170:http (CLOSE_WAIT) java 26371 root 96u IPv4 149724978 0t0 TCP izbp10ebr6tsvo83iahgzdz:48287->47.111.38.212:http (CLOSE_WAIT)
3-lsof输出各列信息的意义如下：
COMMAND：进程的名称 PID：进程标识符
USER：进程所有者
FD：文件描述符，应用程序通过文件描述符识别该文件。如cwd、txt等 TYPE：文件类型，如DIR、REG等
DEVICE：指定磁盘的名称
SIZE：文件的大小
NODE：索引节点（文件在磁盘上的标识）
NAME：打开文件的确切名称
FD 列中的文件描述符cwd 值表示应用程序的当前工作目录，这是该应用程序启动的目录，除非它本身对这个目录进行更改,txt 类型的文件是程序代码，如应用程序二进制文件本身或共享库，如上列表中显示的 /sbin/init 程序。
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