Simple regex
Regex quick reference
| [abc] | A single character: a, b or c |
| [^abc] | Any single character but 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 |