6.2 Context-Sensitive Replacement
The simplest global replacements substitute one word (or a phrase) for another. If you have typed a file with several misspellings (editer for editor ), you can do the global replacement:
This substitutes editor for every occurrence of editer throughout the file.
There is a second, slightly more complex syntax for global replacement. This syntax lets you search for a pattern, and then, once you find the line with the pattern, make a substitution on a string different from the pattern. You can think of this as context-sensitive replacement.
The syntax is as follows:
For example, in this book, the SGML directives
If the pattern being used to find the line is the same as the one you want to change, you don't have to repeat it. The command:
would search for lines containing string and substitute for that same string .
has the same effect as:
You can save some typing by using the second form.
It is also possible to combine the