Commanding at the sed Editor Basics
The key to successfully using the sed editor is to know its myriad of commands and formats, which help you to customize your text editing. This section describes some of the basic commands and features you can incorporate into your script to start using the sed editor.
Introducing more substitution options
You've already seen how to use the s command to substitute new text for the text in a line. However, a few additional options are available for the substitute command that can help make your life easier.
Substituting flags
There's a caveat to how the substitute command replaces matching patterns in the text string. Watch what happens in this example:
$ cat data4.txt
This is a test of the test script.
This is the second test of the test script.
$
$ sed 's/test/trial/' data4.txt
This is a trial of the test script.
This is the second trial of the test script.
$The substitute command works fine in replacing text in multiple lines...