Under linux view the process id when used in command

A view port occupied by the process

1. lsof -i: port number to see a port of occupancy

1 lsof -. I: port number, view a port occupancy 
[root @ localhost bin] # lsof -i: 8080 
the COMMAND PID the USER FD the TYPE the DEVICE SIZE / OFF NODE NAME 
the Java 3511 root 46U IPv6 31351 0t0 TCP * : webcache (LISTEN) 
the COMMAND: be famous, as explained above 8080 occupied a java process 
PID: ID process, when the process is designated generally kill the process PID 
the USER: process owners

2.netstat -ntlp: View all current tcp port

Combined with grep can check the occupancy of a specific port number 
netstat -tunlp | grep port number, view the port occupancy 
-t, be given the option of tcp 
-u, udp given the option of 
-n, refused to show the alias can display numbers all converted to digital 
-l, lists only in listen (listen) service state 
program name -p, show the establishment of related links

[root @ localhost bin] # netstat -tunlp | grep 8080 
tcp6        0       0 ::: 8080                  ::: * LISTEN       3511 / the Java 
These results indicate 8080 port is a process ID of the Java process for the 3511 occupation 

[root @ ops01 ~] # -tunlp netstat | grep 3000 
tcp6        0       0 ::: 3000                  ::: * LISTEN       13298 / node / u01 / WSS 
above results indicate 3000 port is a process ID of the node program occupies 13298

Second, according to the program name query process ID

1. ps -ef | grep process name 
ps -ef all processes are displayed

UID：进程拥有者
PID：进程ID
PPID：上级父程序的ID
C:  CPU 使用的资源百分比
STIME： 系统启动时间
TTY：登入者的终端机位置
TIME：使用掉的 CPU 时间
CMD：所下达的指令名称 

例如查询nginx相关进程状态
[root@ops01 ~]# ps -ef|grep nginx