Книги автора: Learning GNU Emacs, 3rd Edition
/ Книги автора: Learning GNU Emacs, 3rd Edition
/ Книги автора: Learning GNU Emacs, 3rd Edition
/ Книги автора: Learning GNU Emacs, 3rd Edition
Искусство программирования для UnixThe Art of Unix Programming
/ Книги автора: Learning GNU Emacs, 3rd Edition
Книга: Learning GNU Emacs, 3rd Edition
11.3.2.5 Regular expression operator summary
11.3.2.5 Regular expression operator summary
Table 11-6 concludes our discussion of regular expression operators with a reference list of all the operators covered.
Table 11-6. Regular expression operators
Operator | Function |
---|---|
. |
Match any character. |
* |
Match 0 or more occurrences of preceding char or group. |
+ |
Match 1 or more occurrences of preceding char or group. |
? |
Match 0 or 1 occurrences of preceding char or group. |
[...] |
Set of characters; see below. |
( |
Begin a group. |
) |
End a group. |
| |
Match the subexpression before or after |. |
^ |
At beginning of regexp, match beginning of line or string. |
$ |
At end of regexp, match end of line or string. |
n | Match Newline within a regexp. |
t |
Match Tab within a regexp. |
< |
Match beginning of word. |
> |
Match end of word. |
The following operators are meaningful within character sets: | |
^ |
At beginning of set, treat set as chars not to match. |
- (dash) |
Specify range of characters. |
The following is also meaningful in regexp replace strings: | |
n |
Substitute portion of match within the n th ( and ) , counting from left ( to right, starting with 1. |
Finally, the following characters are operators (not discussed here) when double-backslash-escaped: b, B, c
, C
, w
, W
, s, S, =
, _
, '
, and `
. Thus, these are "booby traps" when double-backslash-escaped. Some of these behave similarly to the character class aliases you may have encountered in Perl and Java regular expressions.
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