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Manual Reference Pages  - HTTP::Headers::Util (3)

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HTTP::Headers::Util - Header value parsing utility functions

CONTENTS

  use HTTP::Headers::Util qw(split_header_words);
  @values = split_header_words($h->header("Content-Type"));

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 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\""]
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 1997-1998, Gisle Aas

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

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