NAME Text::Header - RFC 822/2068 `header' and `unheader' functions SYNOPSIS use Text::Header; # header and unheader exported # Construct headers similar to CGI.pm and HTTP::Headers @HEADERS = header(content_type => 'text/html', author => 'Nathan Wiger', last_modified => $date, accept => [qw(text/html text/plain)]); # The above produces the array: @HEADERS = ("Content-Type: text/html\n", "Author: Nathan Wiger\n", "Last-Modified: Wed Sep 27 13:31:06 PDT 2000\n", "Accept: text/html, text/plain\n"); # Can also construct SMTP headers to format mail @mail_headers = header(from => 'Nathan Wiger ', to => 'perl5-porters@perl.org'); print $MAIL @mail_headers, "\nKeep up the great work!\n"; # The above would print this to the $MAIL handle: From: Nathan Wiger To: perl5-porters@perl.org Keep up the great work! DESCRIPTION This module provides two new functions, `header' and `unheader', which provide general-purpose RFC 822 header construction and parsing. They do not provide any intelligent defaults of HTTP-specific methods. They are simply aimed at providing an easy means to address the mechanics of header parsing. The output style is designed to mimic `CGI.pm' and `HTTP::Headers', so that users familiar with these interfaces will feel at home with these functions. As shown above, the `headers' function automatically does the following: 1. uc's the first letter of each tag token and lc's the rest, also converting _'s to -'s automatically 2. Adds a colon separating each tag and its value, and exactly one newline after each one 3. Combines list elements into a comma-delimited string Note that a list is always joined into a comma-delimited string. To insert multiple separate headers, simply call `header' with multiple args: push @out, header(accept => 'text/html', accept => 'text/plain'); This would create multiple "Accept:" lines. Note that unlike `CGI.pm', the `header' function provided here does not provide any intelligent defaults. If called as: @out_headers = header; It will return an empty list. This allows `header' to be more general pupose, so it can provide SMTP and other headers as well. You can also use it as a generic text formatting tool, hence the reason it's under the `Text::' hierarchy. The `unheader' function works in exactly the opposite direction from `header', pulling apart headers and returning a list. `unheader': 1. lc's the entire tag name, converting -'s to _'s 2. Separates each tag based on the colon delimiter, chomping newlines. 3. Returns a list of tag/value pairs for easy assignment to a hash So, assuming the `@HEADERS' array shown up top: %myheaders = unheader(@HEADERS); The hash `%myheaders' would have the following values: %myheaders = ( content_type => 'text/html', author => 'Nathan Wiger', last_modified => 'Wed Sep 27 13:31:06 PDT 2000', accept => 'text/html, text/plain' ); Note that all keys are converted to lowercase, and their values have their newlines stripped. However, note that comma-separated fields are not split up on input. This cannot be done reliably because some fields, such as the HTTP `Date:' header, can contain commas even though they are not lists. Inferring this type of structure would require knowledge of content, and these functions are specifically designed to be content-independent. The `unheader' function will respect line wrapping, as seen in SMTP headers. It will simply join the lines and return the value, so that: %mail = unheader("To: Nathan Wiger , perl5-porters@perl.org"); Would return: $mail{to} = "Nathan Wiger , perl5-porters@perl.org" Notice that multiple spaces between the comma separator have been condensed to a single space. Since the `header' and `unheader' functions are direct inverses, this call: @out = header unheader @in; Will result in `@out' being exactly equivalent to `@in'. REFERENCES This is designed as both a Perl 5 module and also a Perl 6 prototype. Please see the Perl 6 proposal at http://dev.perl.org/rfc/333.html This module is designed to be fully compliant with the internet standards RFC 822 (SMTP Headers) and RFC 2068 (HTTP Headers). AUTHOR Copyright (c) 2000 Nathan Wiger . All Rights Reserved. This module is free software; you may copy this under the terms of the GNU General Public License, or the Artistic License, copies of which should have accompanied your Perl kit.