\ | general escape character with several uses |
^ | assert start of subject (or line, in multiline mode) |
$ | assert end of subject or before a terminating newline (or
end of line, in multiline mode) |
. | match any character except newline (by default) |
[ | start character class definition |
] | end character class definition |
| | start of alternative branch |
( | start subpattern |
) | end subpattern |
? | extends the meaning of (, also 0 or 1 quantifier, also makes greedy
quantifiers lazy (see repetition) |
* | 0 or more quantifier |
+ | 1 or more quantifier |
{ | start min/max quantifier |
} | end min/max quantifier |