Regex quick reference
[abc] |
A single character of: a, b or c |
[^abc] |
Any single character except: a, b, or c |
[a-z] |
Any single character in the range a-z |
[a-zA-Z] |
Any single character in the range a-z or A-Z |
| Start of line |
$ |
End of line |
\A |
Start of string |
\z |
End of string |
. |
Any single character |
\s |
Any whitespace character |
\S |
Any non-whitespace character |
\d |
Any digit |
\D |
Any non-digit |
\w |
Any word character (letter, number, underscore) |
\W |
Any non-word character |
\b |
Any word boundary character |
(...) |
Capture everything enclosed |
(a|b) |
a or b |
a? |
Zero or one of a |
a* |
Zero or more of a |
a+ |
One or more of a |
a{3} |
Exactly 3 of a |
a{3,} |
3 or more of a |
a{3,6} |
Between 3 and 6 of a |
options:
i case insensitive
m make dot match newlines
x ignore whitespace in regex
o perform #{...} substitutions only once
For a complete Ruby regex guide, see the Pickaxe.
