Supported Metacharacters
PCRE supports the metacharacters and metasequences listed in Table 43 through Table 47. For expanded definitions of each metacharacter, see "Regex Metacharacters, Modes, and Constructs.”
Sequence | Meaning |
| Alert (bell), |
| Backspace, |
| Escape character, |
| Newline, |
| Carriage return, |
| Form feed, |
| Horizontal tab, |
| Character specified by a three-digit octal code. |
| Character specified by a one- or two-digit hexadecimal code. |
| Character specified by any hexadecimal code. |
| Named control character. |
| Character contained by given Unicode block or property. |
| Character not contained by given Unicode block or property. |
Class | Meaning |
| A single character listed, or contained in a listed range. |
| A single character not listed, and not contained within a listed range. |
| POSIX-style character class valid only within a regex character class. |
| Any character, except newline (unless single-line mode, |
| One byte; however, this may corrupt a Unicode character stream. |
| Word character, |
| Nonword character, |
| Digit character, |
| Nondigit character, |
| Whitespace character, |
| Nonwhitespace character, |
| Unicode newline sequence. |
Sequence | Meaning |
| Start of string, ... |
Get Regular Expression Pocket Reference, 2nd Edition now with O’Reilly online learning.
O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.