HTTP::Headers::Util - Header value parsing utility functions
version 6.44
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:
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 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
_split_header_words 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"
Gisle Aas <gisle@activestate.com>
This software is copyright (c) 1994 by Gisle Aas.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.