Htaccess – regular expressions
Version: 16.1a
Revision: 33 Build 18
Htaccess – regular expressions
Introduction: many users these days aren’t sure about “htaccess” syntax and their regular expressions. So, I’ve written this article to stop you from getting confuse!
. (full stop) – match any character and any single character
* (asterix) – match zero or more of the previous symbol
———————————
Notes: * – means one or more of the preceding characters
+ (plus) – match one or more of the previous symbol
? (question) – match zero or one of the previous symbol
\? (backslash-something) – match any special characters
^ (caret symbol) – match the start of a string
# – this symbol is for writing comments and notes
——————————–
Notes: ^ – refers to the beginning of a string. So any syntax that has ^ in it means “starts with”
$ (dollar symbol) – match the end of a string
——————————–
Notes: $ – refers to the end of the string. So any syntax that ends with $ means “ends with” the previous character
[set] – match any of the symbols inside the square brackets
(pattern) – grouping – remember what the pattern matched as a special variable
Extended information
——————————–
^$ – refers to a string that starts and stops with nothing in between, also known as an empty string, as there’s nothing in it.
^demo.* – refers to a string that starts with “demo” and then may contain any number of any characters.
^globalnews\.co.uk$ – refers to a string that contains only “lair360.co.uk”
! symbol is a negation. Anywhere you see a ! (exclamation mark), it means denied or exclude. So, “!string”, matches everything except (exclude) string.
Exclusion is a very useful method and it will allow your domain from being block by htaccess as bad referrers and agent-robots.
!^friend1@client1.mydomain\.com$
Notes: the ! symbol notify the engine to exclude “friend1@client1.mydomain” from a “.com” domain. This way, your website or friend’s site will not get block.
——————————–
Advice: ^(.*)$ – the ^ (caret) symbol defines the start, (.*) is a designated variable (using brackets) containing a regular expression that matches any combination of characters. But, the $ symbol defines the end.
That is all for today and thank you for reading!
Copyrighted by Lair360
