|
| Character | Meaning |
|---|
| \ | Indicates next character should not be interpreted literally if it normally is, and should be interpreted literally if it normally isn't. |
| ^ | Matches beginning of input or line. |
| $ | Matches end of input or line. |
| * | Matches 0 or more instances of preceding character. |
| + | Matches 1 or more instances of preceding character. |
| ? | Matches 0 or 1 instances of preceding character. |
| . | Matches any single character other than the newline character. |
| (x) | Matches x and remembers the match. |
| x|y | Matches either x or y. |
| {n} | Matches exactly n instances of preceding character (where n is an integer). |
| {n,} | Matches at least n instances of preceding character (where n is an integer). |
| {n,m} | Matches it least n and at most m instances of preceding character (where n and m are integers). |
| [xyz] | Matches any one of enclosed characters (specify range using hyphen, such as [0-9]. |
| [^xyz] | Matches any character not enclosed (specify range using hyphen, such as [^0-9]. |
| [\b] | Matches a backspace. |
| \b | Matches a word boundary, such as a space. |
| \B | Matches a nonword boundary. |
| \cX | Matches a control character, X. |
| \d | Matches a digit character (same as [0-9]). |
| \D | Matches a nondigit character (same as [^0-9]). |
| \f | Matches a form feed. |
| \n | Matches a line feed. |
| \r | Matches a carriage return. |
| \s | Matches a single white space character, including space, tab, form feed, and line feed (same as [\f\n\r\t\v]). |
| \S | Matches a single non-white-space character (same as [^\f\n\r\t\v]). |
| \t | Matches a tab. |
| \v | Matches a vertical tab. |
| \w | Matches any alphanumeric character, including the underscore (same as [A-Za-z0-9_]). |
| \W | Matches any nonword character (same as [^A-Za-z0-9_]). |
| \n | A reference to the last substring matching the nth parenthetical (where n is a positive integer). |
\ooctal
\xhex | Matches an octal or hexadecimal escape value (for embedding ASCII codes). |
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