The format of both books is the same: one-line scripts followed by detailed commentary. However, the
sed book takes more effort to read because the content is more subtle. The
awk book covers the most basic features of
awk, but the
sed book goes into the more advanced features of
Sed One-Liners Explained provides clear explanations of features I found hard to understand from reading the sed documentation. If you want to learn
sed in depth, this is a great book. But you may not want to learn
sed in depth; the oldest and simplest parts of
sed offer the greatest return on time invested. Since the book is organized by task — line numbering, selective printing, etc — rather than by language feature, the advanced and basic features are mingled.
On the other hand, there are two appendices organized by language feature. Depending on your learning style, you may want to read the appendices first or jump into the examples and refer to the appendices only as needed.
For a sample of the book, see the table of contents, preface, and first chapter here.