HTTP::Headers::Util(3) User Contributed Perl Documentation HTTP::Headers::Util(3)
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 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 => '"fooar"']
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.
libwww-perl-5.65 2000-09-16 HTTP::Headers::Util(3)