Regular Expressions Special Characters
| CHARACTER | MATCHES |
\ |
Toggles between literal and special characters. For example, "\w" means the special value of "\w" (see below) |
^ |
Beginning of a string |
$ |
End of a string |
* |
Zero or more times |
+ |
One or more times |
? |
Zero or one time |
. |
Any character except newline |
\b |
Word boundary |
\B |
Non-word boundary |
\d |
Any digit o through 9 (same as [o-9]) |
\D |
Any non-digit |
\f |
Form feed |
\n |
New line |
\r |
Carriage return |
\s |
Any single white space character (same as[\f\n\r\t\v]) |
\S |
Any single non-white space character |
\t |
Tab |
\v |
Vertical Tab |
\w |
Any letter, number, or the underscore (same as[a-zA-Zo-9_]) |
\W |
Any character other than a letter, number, or underscore |
\xnn |
The ASCII character defined by the hexadecimal number nn |
\onn |
The ASCII character defined by the octal number nn |
\cx |
The control character X |
[abcde] |
A character set that matches any one of the enclosed characters |
[^abcde] |
A complemented or negated character set; one that does not match any of the enclosed characters |
[a-e] |
A character set that matches any one in the range of enclosed characters |
[\b] |
The literal backspace character (different from \b) |
{n} |
Exactly n occurrences of the previous character |
{n,} |
At least n occurrences of the previous character |
{n,m} |
Between n and m occurrences of the previous character |
() |
A grouping, which is also stored for later use |
x|y |
Either x or y |
| REGULAR EXPRESSION MODIFIERS | |
g |
Search for all possible matches (globally), not just the first |
i |
Search without case-sensitivity |