- Zip your answers into a single compressed file and submit it to Blackboard. Part A: Regular Expressions You can put your answers in this part into text files. Use Ix1 - Ix4 to do the tasks. PROBLEM 1: (IPV4) IPv4 address is a numerical label such as 127.0.0.1 used in computer networks for communication. The format of the address is xyz.w where x,y,z,w are integers in the range [0,255]. Suppose you have a file where each line contains a numerical label that may be a valid IPv4 address or not. Task: Use grep to extract all lines that contain valid IPv4 addresses. PROBLEM 2: (English name)