Pipeline (pipe) is a very important Linux command. It can use the output of one command as the input of another command, thus connecting two or more commands together for execution. It is a method of communication between processes and used to transfer data. How to use: The pipe symbol "|" is used to concatenate commands, for example:
ps aux|grep sshd
This command is to connect the ps aux and grep sshd commands in series, query the processes in the system through ps aux, and then filter out the processes containing sshd through the grep command
ps aux|nl|tail -n +2|head -8
Use ps aux to view the system process, and then use nl to display the line number of each line, tail -n +2 to display the file from the second line, head -8 to display the first eight lines; the serialization of this command through the pipeline command The result is (display ps aux to view the process command output information, from line 2 to line 9, and display the line number)
From the above examples, we can see that through pipeline commands, we can flexibly combine different commands to complete more complex operations, thereby achieving more efficient operations. Moreover, multiple commands can be connected in series by using the pipeline command, which reduces the trouble of entering multiple commands on the command line.