CMD command line command pipeline

First, what is the pipe command 
　　pipeline will be able to command a command execution result filtered, leaving only the information we need. 
　　As dir command displays all folders and directory files, you can use the pipe command | findstr "" The results of the screening dir, leaving only the required information

 

 

 

 

 

 

 

reference

Both methods cmd under the name of the filter file