In this example, we will print just the received data from the eth0 interface.
Using just the ifconfig eth0 command, a heap of data can be printed to the screen. To show just the packets received, we can isolate the lines that contain RX packets (RX for received). This is where grep comes in:
$ ifconfig eth0 | grep "RX packets"
Using the pipe or vertical bars, we can take the output of the ifconfig command and ...