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Metacharacters Defined
|
MChar | Definition |
^ |
Start of a string. |
$ |
End of a string. |
. |
Any character (except
newline) |
| |
Alternation. |
{...} |
Explicit quantifier notation. |
[...] |
Explicit set of characters to match. |
(...) |
Logical grouping of part of an expression. |
* |
0 or more of previous expression. |
+ |
1 or more of previous expression. |
? |
0 or 1 of previous expression; also forces minimal matching when an expression might match several strings within a search string. |
|
Preceding one of the above, it makes it a literal instead of a special character. Preceding a special matching character, see below. |
Metacharacter Examples
|
Pattern | Sample Matches |
^abc |
abc, abcdefg, abc123, ... |
abc$ |
abc, endsinabc, 123abc, ... |
a.c |
abc, aac, acc, adc, aec, ... |
bill|ted |
ted, bill |
ab{2}c |
abbc |
a[bB]c |
abc, aBc |
(abc){2} |
abcabc |
ab*c |
ac, abc, abbc, abbbc, ... |
ab+c |
abc, abbc, abbbc, ... |
ab?c |
ac, abc |
asc |
a c |
|
Escaped Char | Description |
ordinary characters |
Characters other than . $ ^ { [ ( | ) ] } * + ? match themselves. |
a |
Matches a bell (alarm) u0007. |
|
Matches a backspace u0008 if in a []; otherwise matches a word boundary (between w and W characters). |
|
Matches a tab u0009. |
|
Matches a carriage return u000D. |
v |
Matches a vertical tab u000B. |
f |
Matches a form feed u000C. |
|
Matches a new line u000A. |
e |
Matches an escape u001B. |
|