Looking at Multiline Commands
When using the basic sed editor commands, you may have noticed a limitation. All the sed editor commands perform functions on a single line of data. As the sed editor reads a data stream, it divides the data into lines based on the presence of newline characters. The sed editor handles each data line one at a time, processing the defined script commands on the data line, and then moving on to the next line and repeating the processing.
Sometimes, you need to perform actions on data that spans more than one line. This is especially true if you're trying to find or replace a phrase.
For example, if you're looking for the phrase Linux System Administrators Group in your data, it's quite possible that the phrase's words can be split onto two lines. If you processed the text using a normal sed editor command, it would be impossible to detect the split phrase.
Fortunately, the designers behind the sed editor thought of that situation and devised...
