| ^ |
Matches beginning of line. |
| $ |
Matches end of line. |
| . |
Matches any single character except newline. Using m option allows it to match newline as well. |
| [...] |
Matches any single character in brackets. |
| [^...] |
Matches any single character not in brackets |
| \A |
Beginning of entire string |
| \z |
End of entire string |
| \Z |
End of entire string except allowable final line terminator. |
| re* |
Matches 0 or more occurrences of preceding expression. |
| re+ |
Matches 1 or more of the previous thing |
| re? |
Matches 0 or 1 occurrence of preceding expression. |
| re{ |
n} Matches exactly n number of occurrences of preceding expression. |
| re{ |
n,} Matches n or more occurrences of preceding expression. |
| re{ |
n, m} Matches at least n and at most m occurrences of preceding expression. |
| a |
b |
| (re) |
Groups regular expressions and remembers matched text. |
| (?: |
re) Groups regular expressions without remembering matched text. |
| (?> |
re) Matches independent pattern without backtracking. |
| \w |
Matches word characters. |
| \W |
Matches nonword characters. |
| \s |
Matches whitespace. Equivalent to [\t\n\r\f]. |
| \S |
Matches nonwhitespace. |
| \d |
Matches digits. Equivalent to [0-9]. |
| \D |
Matches nondigits. |
| \A |
Matches beginning of string. |
| \Z |
Matches end of string. If a newline exists, it matches just before newline. |
| \z |
Matches end of string. |
| \G |
Matches point where last match finished. |
| \n |
Back-reference to capture group number "n" |
| \b |
Matches word boundaries when outside brackets. Matches backspace (0x08) when inside brackets. |
| \B |
Matches nonword boundaries. |
| \n, |
\t, etc. Matches newlines, carriage returns, tabs, etc. |
| \Q |
Escape (quote) all characters up to \E |
| \E |
Ends quoting begun with \Q |