Pattern | Result |
---|---|
. | Matches any character except newline |
[a-z0-9] | Matches any single character of set |
[^a-z0-9] | Matches any single character not in set |
\d | Matches a digit, same as [0-9] |
\D | Matches a non-digit, same as [^0-9] |
\w | Matches an alphanumeric (word) character [a-zA-Z0-9_] |
\W | Matches a non-word character [^a-zA-Z0-9_] |
\s | Matches a whitespace character (space, tab, newline...) |
\S | Matches a non-whitespace character |
  |   |
\n | Matches a newline |
\r | Matches a return |
\t | Matches a tab |
\f | Matches a formfeed |
\b | Matches a backspace (inside [] only) |
\0 | Matches a null character |
\000 | Also matches a null character because ... |
\nnn | Matches an ASCII character of that octal value |
\xnn | Matches an ASCII character of that hexadicimal value |
\cX | Matches an ASCII control character |
\metachar | Matches the character itself (\|,\.,\*...) |
  |   |
(abc) | Rembers the match for later backreferences |
\1 | Matches whatever the first set of parens matched |
\2 | Matches whatever the second set of parens matched |
\3 | and so on... |
  |   |
x? | Matches 0 or 1 x's, where x is any of the above |
x* | Matches 0 or more x's |
x+ | Matches 1 or more x's |
x{m,n} | Matches at least m x's but nore more than n |
  |   |
abc | Matches all of a, b, and c in order |
fee|fie|foe | Matches one of fee, fie, or foe |
  |   |
\b | Matches a word boundry (outside [ ] only) |
\B | Matches a non-word boundry |
^ | Anchors match to the beginning of a line or string |
$ | Anchors match to the end of a line or string |