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17.8. Using Search Patterns and Global Commands

Besides using line numbers and address symbols (., $, %), ex (including the ex mode of vi, of course) can address lines (Section 20.3) using search patterns (Section 32.1). For example:

:/pattern/d
Deletes the next line containing pattern.

:/pattern/+d
Deletes the line below the next line containing pattern. (You could also use +1 instead of + alone.)

:/pattern1/,/pattern2/d
Deletes from the next line (after the current line) that contains pattern1 through the next following line that contains pattern2.

:.,/pattern/m23
Takes text from current line (.) through the next line containing pattern and puts it after line 23.

Note that patterns are delimited by a slash both before and after.

If you make deletions by pattern with vi and ex, there is a difference in the way the two editors operate. Suppose you have in your file named practice the following lines:

With a screen editor you can scroll the
page, move the cursor, delete lines, insert
characters and more, while seeing results
of your edits as you make them.

Key-strokes

Action

Results

d/while

The vi delete-to-pattern command deletes from the cursor up to the word while but leaves the remainder of both lines.

With a screen editor you can scroll the
page, move the cursor, while seeing results
of your edits as you make them.

:.,/while/d

The ex command deletes the entire range of addressed lines; in this case both the current line and the line containing the pattern. All lines are deleted in their entirety.

With a screen editor you can scroll the
of your edits as you make them.

17.8.1. Global Searches

In vi you use a / (slash) to search for patterns of characters in your files. By contrast, ex has a global command, g, that lets you search for a pattern and display all lines containing the pattern when it finds them. The command :g! does the opposite of :g. Use :g! (or its synonym :v) to search for all lines that do not contain pattern.

You can use the global command on all lines in the file, or you can use line addresses to limit a global search to specified lines or to a range of lines.

:g/pattern/
Finds (moves to) the last occurrence of pattern in the file.

:g/pattern/p
Finds and displays all lines in the file containing pattern.

:g!/pattern/nu
Finds and displays all lines in the file that don't contain pattern; also displays line number for each line found.

:60,124g/pattern/p
Finds and displays any lines between 60 and 124 containing pattern.

g can also be used for global replacements. For example, to search for all lines that begin with WARNING: and change the first word not on those lines to NOT:

:g/^WARNING:/s/\<not\>/NOT/

-- LL, from Learning the vi Editor (O'Reilly, 1998)



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