Regexp

BASIC METACHARACTERS   SPECIFIC CHARACTERS (cont)
. Match any single character   \S Match anything but white space character
| Or   \t Tab
[] Match one of a set of characters   \v Vertical tab
[^] Negate a set of characters   \w Match any alphanumeric character, digit or underscore
- Define a range of characters eg. [0-9]   \W Opposite of \w
  Escape the next character   \x Match a hexadecimal number
QUANTIFIERS   \0 Match octal number
* Match zero or more of the previous character   BACKREFERENCES & LOOKAROUND
*? Lazy version of *   () Define subexpression
+ Match one or more of the previous character   \n Match nth subexpression
+? Lazy version of +   ?= Lookahead
? Match zero or one of the previous character   ?! Negative lookahead
{n} Match exact number of instances   CASE CONVERSION
{m,n} Match a range of instances   \E Terminate \L or \U
{n,} Match n or more instances   \l Convert next character to lowercase
{n,}? Lazy version on {n,}   \L Convert all characters up to \E to lowercase
ANCHORS   \u Convert next character to uppercase
^ Match  start of string   \U Convert all characters up to \E to uppercase
\A Match start of string   MODIFIERS
$ Match end of string   (?m) Multiline mode
\Z Match end of string   POSIX
\< Match start of word   [:alnum:] Any letter or digit
\> Match end of word   [:alpha:] Any letter
\b Match a word boundary   [:blank:] Space or tab
\B Opposite of \b   [:cntrl:] ASCII control
SPECIFIC CHARACTERS   [:digit:] Any digit
[\b] Backspace   [:print:] Any printable character
\c Match a control character   [:graph:] Same as [:print:] but excludes space
\d Match any digit   [:lower:] Any lower case character
\D Opposite of \d   [:punct:] Any character that is in not [:alnum:] or [:cntrl:]
\f Form feed   [:space:] Any whitespace character including space
\n Line feed   [:upper:] Any uppercase character
\r Carriage return   [:xdigit:] Any hexadecimal digit
\s Match any white space character