In Section 3.8.1, we used the read dcf () function to read the key: value data in the email headers. In this exercise, we use regular expressions to extract the keys and their values from the header.
The first step in the process is to find the continuation lines for a value, and then collapse them with the first line of the value.
These continuation lines start with either a blank space or a tab character. Use regular expressions to locate them. Then paste them to the first line of the value.
Next break the revised set of key value strings into the keys and values. Again use regular expressions to do this. Then create the names vector from these keys and values.