Header value parsing utility functions
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 \s-1HTTP\s0 header values. None of the functions are exported by default.
The following functions are available: 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 \*(L",\*(R", \*(L";\*(R" and \*(L"=\*(R" as well as quoted values after \*(L"=\*(R". A list of space separated tokens are parsed as if they were separated by \*(L";\*(R". If the @header_values passed as argument contains multiple values, then they are treated as if they were a single value separated by comma \*(L",\*(R". This means that this function is useful for parsing header fields that follow this syntax (\s-1BNF\s0 as from the \s-1HTTP/1\s0.1 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 \*(C`undef\*(C'. Syntactically incorrect headers will not necessarily 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 \*(C`_split_header_words\*(C' instead (with a leading underscore). 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.