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@cozingo
Last active November 21, 2023 01:50
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Regex regex
ErrorDocument 404 /errors/400.html
\d - digit [0,9]
\w - digit, ASCII letter or underscore
\s - whitespace, i.e. space, tab, newline(\n), carriage return(\r), vertical tab(Ctrl + K) <-vertical tab not useful anymore
\D == [^\d] - 1 character which is not digit
\W == [^\w] - 1 character which is not ASCII letter, digit and underscore
\S == [^\s] - 1 character which is not type of whitespace
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^ - Start of string, Ex : ^abc accept if string starts with abc
$ - End of string or end of line, Ex: .*? the end$ -> this is the end
. - Any character except \n (line break)
\ - Escape character for reserved words. Ex : 1) \.\*\+\? \$\^\/\\ -> *+? $^/\ 2) \[\{\(\)\}\] -> [{()}]
? - 1 time on none Ex : plurals? plural
* - 0 or more Ex: A*B*C* AAACC
+ - 1 or more
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{3} - exactly 3 times, Ex: \D{3} -> ABC
{2,4} - 2 to 4 times, Ex: \d{2,4} -> 156
{3,} - 3 or more times Ex: \w{3,} regex_tutorial
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| - OR operand, Ex: 22|33 -> 33
(…) - Capturing group, Ex: A(nt|pple) -> Apple (captures "pple")
\1 - Type of First Group parantheses, Ex: r(\w)g\1x -> regex(Here is \1 is type of \w)
\2 - Type of Second Group parantheses, (\d\d)\+(\W\d)=\2\+\1 -> 12+,5=,5+12(Here is \1 is type of \d\d and \2 is type of \W\d)
(?:…) - Non-capturing group, Ex: A(?:nt|pple) -> Apple(Here is pple or not "nt" is acceptable)
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[ … ] - One of the characters in the brackets, Ex: 1)[AEIOU] -> 1 uppercase vowel 2) T[ao]p -> Tap or Top
- - Range indicator, Ex: [a-z] -> 1 lowercase letter
Ex: [x-y] - One of the characters in the range from x to y
[^x] - One character that is not x
[^x-y] - One of the characters not in the range from x to y
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\t - tab character, Ex: T\t\w{2} -> T ab
\r - carriage return
\n - Line feed
\r\n - Line separator on Windows
\h - 1 horizontal whitespace character: tab or Unicode space separator
\N - [^\n] 1 character is not \n
\H - [^\h] 1 character is not \h
https://www.regextester.com
%1 Refers to a pattern matched in a RewriteCond condition
$1 refers to a pattern matched inside a RewriteRule.
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