Regex Character Definitions for htaccess

#

the # instructs the server to ignore the line. used for including comments. each line of comments requires it’s own #. when including comments, it is good practice to use only letters, numbers, dashes, and underscores. this practice will help eliminate/avoid potential server parsing errors.

[F]

Forbidden: instructs the server to return a 403 Forbidden to the client.

[L]

Last rule: instructs the server to stop rewriting after the preceding directive is processed.

[N]

Next: instructs Apache to rerun the rewrite rule until all rewriting directives have been achieved.

[G]

Gone: instructs the server to deliver Gone (no longer exists) status message.

[P]

Proxy: instructs server to handle requests by mod_proxy

[C]

Chain: instructs server to chain the current rule with the previous rule.

[R]

Redirect: instructs Apache to issue a redirect, causing the browser to request the rewritten/modified URL.

[NC]

No Case: defines any associated argument as case-insensitive. i.e., “NC” = “No Case”.

[PT]

Pass Through: instructs mod_rewrite to pass the rewritten URL back to Apache for further processing.

[OR]

Or: specifies a logical “or” that ties two expressions together such that either one proving true will cause the associated rule to be applied.

[NE]

No Escape: instructs the server to parse output without escaping characters.

[NS]

No Subrequest: instructs the server to skip the directive if internal sub-request.

[QSA]

Append Query String: directs server to add the query string to the end of the expression (URL).

[S=x]

Skip: instructs the server to skip the next “x” number of rules if a match is detected.

[E=variable:value]

Environmental Variable: instructs the server to set the environmental variable “variable” to “value”.

[T=MIME-type]

Mime Type: declares the mime type of the target resource.

[]

specifies a character class, in which any character within the brackets will be a match. e.g., [xyz] will match either an x, y, or z.

[]+

character class in which any combination of items within the brackets will be a match. e.g., [xyz]+ will match any number of x’s, y’s, z’s, or any combination of these characters.

[^]

specifies not within a character class. e.g., [^xyz] will match any character that is neither x, y, nor z.

[a-z]

a dash (-) between two characters within a character class ([]) denotes the range of characters between them. e.g., [a-zA-Z] matches all lowercase and uppercase letters from a to z.

a{n}

specifies an exact number, n, of the preceding character. e.g., x{3} matches exactly three x’s.

a{n,}

specifies n or more of the preceding character. e.g., x{3,} matches three or more x’s.

a{n,m}

specifies a range of numbers, between n and m, of the preceding character. e.g., x{3,7} matches three, four, five, six, or seven x’s.

()

used to group characters together, thereby considering them as a single unit. e.g., (perishable)?press will match press, with or without the perishable prefix.

^

denotes the beginning of a regex (regex = regular expression) test string. i.e., begin argument with the proceeding character.

$

denotes the end of a regex (regex = regular expression) test string. i.e., end argument with the previous character.

?

declares as optional the preceding character. e.g., monzas? will match monza or monzas, while mon(za)? will match either mon or monza. i.e., x? matches zero or one of x.

!

declares negation. e.g., “!string” matches everything except “string”.

.

a dot (or period) indicates any single arbitrary character.

-

instructs “not to” rewrite the URL, as in “...domain.com.* - [F]”.

+

matches one or more of the preceding character. e.g., G+ matches one or more G’s, while “+” will match one or more characters of any kind.

*

matches zero or more of the preceding character. e.g., use “.*” as a wildcard.

|

declares a logical “or” operator. for example, (x|y) matches x or y.

\

escapes special characters ( ^ $ ! . * | ). e.g., use “\.” to indicate/escape a literal dot.

\.

indicates a literal dot (escaped).

/*

zero or more slashes.

.*

zero or more arbitrary characters.

^$

defines an empty string.

^.*$

the standard pattern for matching everything.

[^/.]

defines one character that is neither a slash nor a dot.

[^/.]+

defines any number of characters which contains neither slash nor dot.

http://

this is a literal statement — in this case, the literal character string, “http://”.

^domain.*

defines a string that begins with the term “domain”, which then may be proceeded by any number of any characters.

^domain\.com$

defines the exact string “domain.com”.

-d

tests if string is an existing directory

-f

tests if string is an existing file

-s

tests if file in test string has a non-zero value