Use of lower 1.linux ps
ps to display the state of the current process
ps a display of all processes
ps -A display all the process information
ps -u root shows a specified user information
ps -ef show all process information, along with the command line
ps -ef | grep ssh find the specified process
ps -l lists the currently belong to own the PID and related information log on to
ps aux lists all current programs are among the memory
ps -axjf lists similar program tree display program
Find out about the cron and syslog both services PID number ps aux | egrep '(cron | syslog)'
2.grep command
grep match filename search for a word in the text, the command will return a line of text that contains "match" of
grep match file1 file2 ... Find text in multiple
grep -v "match" filename output all lines except the -v option
grep "match" filename --color = auto color matching tag
grep -c "text" filename or text file contains statistics the number of rows matched string, and then returns the number of rows
The number of rows grep "match" -n filename output matching string is located
grep "text". -r -n recursive search for text in a multi-level directory
echo "hello world" | character case grep -i "HELLO" Ignore match in style
3.netstat
netstat -a displays all socket, including listening, showing all connections and listening ports
netstat -n display address port numbers in digital form
netstat -r Displays the routing table
netstat -s to display statistics by protocol, the default display IP, Icmp, TCP, UDP
netstat -v Show Details
netstat -tunlp | grep port number to find the port number
netstat -ntulp | grep 80 View all 80 Port Usage
ps -aux | grep tomcat found no tomcat process port 8080
netstat -apn View all processes and port usage
4. Check whether the port is occupied
1. Using the method lsof
Install lsof lsof -i: port number to see if a port is occupied
2. Using netstat
netstat -anp | grep 80 view port 80 is occupied
5. View thread
1. ps -T Spid indicates that the thread ID, CMD thread display name
ps -T -p <pid> lists all the threads created by the process of process ID <pid> the
2. top -H can display real-time individual threads, the view mode is switched on or off
top -H -p <pid> pid output for a particular process and check the threads in the process run case
