Write a bash script which uses 'echo/read' commands to read in the number of packets you want captured.

Using tshark, capture the instructed number of packets on 'any' interface and write to 'file.pcap'.

After its written, using echo, ask the user which protocol to search for in the saved file, using read to assign the value to a variable.

Consequently, use tshark and grep to display any line containing the chosen protocol.

Clues using echo/read commands:

echo -n 'Please enter the number of packets you want captured and press [ENTER] ' read num