Shell common commands - memos

1、 According to the port |pid Troubleshoot problems

netstat -tnlp   View the current port in use and display pid
lsof -i: port   Check who is using the specific port number 
ps -ef|grep 'pid|port'  according to pid Or port 

2、 View route hops

mtr -r  ip  #  Output routing report 
mtr -c(n) ip #  How many packets of data are sent 
mtr # my traceroute

3、 System resource self check

ifconfig -a	| ip a  View NIC 
netstat -tnlp  Check the network port 
iostat 1 10  see io usage 	1  Refresh interval | 10  Refresh times 
vmstat 1 10  Check the overall usage of the system 

top command , View system load 、cpu usage 、 Memory usage , And process list 
free -m  View memory usage 

dstat  Check the in and out rate of the network card 
sar -n DEV 1 10 Check out the Internet 
nethogs  Check the network traffic of the process 
iftop  View source ip And the target ip Network traffic 

4、 Search for commands

locate -i path/ filename  path Optional variables   Ignore case   Default fuzzy query   Index has delay 
find /dir -name filename   stay /dir Under the directory and its subdirectories, look for the name filename The file of 
 Default to current directory , filename Can pass * Symbols realize fuzzy query 
whereis  Can only be used for program name search   Only binary command files can be retrieved 
which  stay PATH In the path specified by the variable , Search for the location of a system command , It is generally used to determine whether the command exists 

5、ufw Simple firewall

ufw allow port  #  Open a port 
ufw delete allow port 
ufw allow from ip  Allow this IP Access all native ports 
ufw allow proto tcp from 192.168.0.0/24 to any port 22   Allowed to specify IP Segments access specific ports 

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6、 Command line http Commissioning

curl -H "Content-Type: application/json" -X POST -d '{"key": "value"}'  http://localhost:2000/api/json
 Transfer files 
curl -H "Content-Type: application/json" -X POST -d @data.json  http://localhost:2000/api/json