Control characters used in above samples
Character |
Meaning |
^ |
Beginning of line |
$ |
End of line |
\s |
Whitespace (a tab or space) |
* |
Zero or more of the preceding character |
? |
Preceding character is optional |
| |
Alternative expression |
( ) |
Subexpressions |
\1 |
Back reference to 1st subexpression |