Metacharacters, Listed by Unix Program

Some metacharacters are valid for one program but not for another. Those that are available to a Unix program are marked by a checkmark (×) in Table 6-1. Items marked with a P are specified by POSIX; double-check your system’s version. Full descriptions are provided after the table.

Table 6-1. Unix metacharacters

Symbol

ed

ex

vi

sed

awk

grep

egrep

Action

a Stored subpatterns can be replayed during matching. See Table 6-2.

.

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. 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.

?

    

 

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 (on the right). The metacharacters in Table ...

Get Mac OS X Tiger in a Nutshell now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.