Regular expression quick start guide
| Regular Expression Pattern | Explanations |
|---|---|
| ^ | Matches beginning of a line |
| $ | Matches the end of a line |
| [characters] | Matches any single character between the brackets |
| re1|re2 | Match either re1 or re2 |
| re* | Matches zero or more occurrences of re |
| re+ | Matches one or more occurrences of re |
| re? | Matches zero or one occurrences of re |
| Re{m,n} | Matches at least “m” and at most “n” occurrences of re |
| (...) | Parentheses are used to group regular expressions |
| \0, \1, \2, ... | Substitute the value matched by the nth grouped sub-expression, used in remapped fields. |