Some metacharacters are valid for one program but not for another. Those that are available to a Unix program are marked by a checkmark (x) 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.
Symbol | ed | ex | vi | sed | awk | grep | egrep | Action |
---|---|---|---|---|---|---|---|---|
. |
|
|
|
|
|
|
| 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. | |||||
a Stored subpatterns can be replayed during matching. See Table 6-2. |
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 6-1 are meaningful only in a search pattern.
In ed , ex , vi , and sed , the metacharacters in Table 6-2 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 |
|
| 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 . |