Metacharacters, Listed by Unix Program

Some metacharacters are valid for one program but not for another. Those that are available are marked by a bullet (·) in Table 7-1. (This table is correct for most commercial Unix systems, including Solaris.) Items marked with a “P” are specified by POSIX; double-check your system’s version. (On Solaris, the versions in /usr/xpg4/bin and /usr/xpg6/bin accept these items.) Full descriptions were provided in the previous section.

Table 7-1. Unix metacharacters

Symbol

ed

ex

vi

sed

awk

grep

egrep

Action

Stored subpatterns can be “replayed” during matching. See Table 7-2.

.

·

·

·

·

·

·

·

Match any character.

*

·

·

·

·

·

·

·

Match zero or more preceding.

^

·

·

·

·

·

·

·

Match beginning of line/string.

$

·

·

·

·

·

·

·

Match end of line/string.

\

·

·

·

·

·

·

·

Escape following character.

[ ]

·

·

·

·

·

·

·

Match one from a set.

\( \)

·

·

·

·

 

·

 

Store pattern for later replay.*

\ 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.

?

    

·

 

·

Match zero or one preceding.

|

    

·

 

·

Separate choices to match.

()

    

·

 

·

Group expressions to match.

Note that in ed, ex, vi, and sed, you specify both a search pattern (on the left) and a replacement pattern ...

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