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Linux in a Nutshell, 6th Edition by Robert Love, Stephen Figgins, Ellen Siever, Arnold Robbins

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Metacharacters, Listed by Program

Some metacharacters are valid for one program but not for another. Those that are available are marked by a bullet (•) in the following table. Items marked with a “P” are specified by POSIX. Full descriptions were provided in the previous section.

Symbol

ed

ex

vi

sed

gawk

grep

egrep

Action

Match any character.

*

Match zero or more preceding characters.

^

Match beginning of line/string.

$

Match end of line/string.

\

Escape following character.

[ ]

Match one from a set.

\( \)

 

 

Store pattern for later replay.[a]

\n

 

 

Replay subpattern in match.

{ }

    

• P

 

• P

Match a range of instances.

\{ \}

  

 

 

Match a range of instances.

\< \>

    

Match word’s beginning or end.

+

    

 

Match one or more preceding characters.

?

    

 

Match zero or one preceding characters.

|

    

 

Separate choices to match.

( )

    

 

Group expressions to match.

[a] Stored subpatterns can be “replayed” during matching. See the following table.

Note that in ed, ex, vi, and sed, you specify both a search pattern (on the left) and a replacement pattern (on the right). The metacharacters listed above are meaningful only in a search pattern.

In ed, ex, vi, and sed, the metacharacters in the following table are valid only in a replacement pattern.

Symbol

ex

vi

sed

ed

Action

\

Escape following character.

\n

Text matching pattern stored in \( \).

&

Text matching search pattern.

~

  

Reuse previous replacement pattern.

%

   

Reuse previous replacement pattern.

\u \U

 

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