6.2 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 bullet () in the table below. Full descriptions are provided after the table.

Symbol	ed	ex	vi	sed	awk	grep	egrep	Action
.								Match any character.
*								Match zero or more preceding.
^								Match beginning of line.
$								Match end of line.
\								Escape character following.
[ ]								Match one from a set.
\( \)								Store pattern for later replay.
\{ \}								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.

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

In ed, ex, and sed, the following additional metacharacters are valid only in a replacement pattern:

Symbol	ex	sed	ed	Action
\				Escape character following.
\ n				Reuse pattern stored in \( \).
&				Reuse previous search pattern.
~				Reuse previous replacement pattern.
\u \U				Change character(s) to uppercase.
\l \L				Change character(s) to lowercase.
\E				Turn off previous \U or \L .
\e				Turn off previous \u or \l .