http::headers::util(3pm)
NAME
HTTP::Headers::Util - Header value parsing utility functions
SYNOPSIS
use HTTP::Headers::Util qw(split_header_words);
@values = split_header_words($h->header("Content-Type"));
DESCRIPTION
This module provides a few functions that helps parsing and
construction of valid HTTP header values. None of the functions are
exported by default.
The following functions are available:
- split_header_words( @header_values )
- This function will parse the header values given as argument into a
list of anonymous arrays containing key/value pairs. The function
knows how to deal with ",", ";" and "=" as well as quoted values
after "=". A list of space separated tokens are parsed as if they were separated by ";". - If the @header_values passed as argument contains multiple values,
then they are treated as if they were a single value separated by
comma ",". - This means that this function is useful for parsing header fields
that follow this syntax (BNF as from the HTTP/1.1 specification,
but we relax the requirement for tokens).
headers = #header
header = (token | parameter) *( [";"] (token | parameter))token = 1*<any CHAR except CTLs or separators>
separators = "(" | ")" | "<" | ">" | "@"| "," | ";" | ":" | "\" | <">
| "/" | "[" | "]" | "?" | "="
| "{" | "}" | SP | HT - quoted-string = ( <"> *(qdtext | quoted-pair ) <"> )
qdtext = <any TEXT except <">>
quoted-pair = "\" CHAR - parameter = attribute "=" value
attribute = token
value = token | quoted-string - Each header is represented by an anonymous array of key/value
pairs. The keys will be all be forced to lower case. The value
for a simple token (not part of a parameter) is "undef".
Syntactically incorrect headers will not necessary be parsed as you would want. - This is easier to describe with some examples:
split_header_words('foo="bar"; port="80,81"; DISCARD, BAR=baz');
split_header_words('text/html; charset="iso-8859-1"');
split_header_words('Basic realm="\\"foo\\\\bar\\""');- will return
[foo=>'bar', port=>'80,81', discard=> undef], [bar=>'baz' ]
['text/html' => undef, charset => 'iso-8859-1']
[basic => undef, realm => "\"foo\\bar\""]- If you don't want the function to convert tokens and attribute keys
to lower case you can call it as "_split_header_words" instead
(with a leading underscore). - join_header_words( @arrays )
- This will do the opposite of the conversion done by
split_header_words(). It takes a list of anonymous arrays as arguments (or a list of key/value pairs) and produces a single
header value. Attribute values are quoted if needed. - Example:
join_header_words(["text/plain" => undef, charset => "iso-8859/1"]);
join_header_words("text/plain" => undef, charset => "iso-8859/1"); - will both return the string:
text/plain; charset="iso-8859/1"
COPYRIGHT
Copyright 1997-1998, Gisle Aas
- This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.