^ | Beginning of a line |
$ | End of a line |
. | Any character |
Expression? | The expression zero or one times |
Expression* | The expression zero or more times |
Expression+ | The expression one or more times |
Expression{n} | The expression n times |
Expression{n,} | The expression at least n times |
Expression{n,m} | The expression at least n but no more than m times |
Expression1|Expression2 | The expression1 or the expression2 |
(Expression) | The expression within the brackets |
\1 \2 ... \n | The content of the nth bracket |
[abc] | One of a, b, or c |
[a-z] | A letter from a to z |
[^abc] | Any letter appart from a, b, and c. |
\t | The character tab |
\n | The character newline |
\r | The character carriage return |
\a | The character alert |
\f | The character form feed |
\e | The character escape |
\cx | The character control-x (a-z) |
\d | Digit |
\D | Non-digit |
\s | Space |
\S | Non-space |