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NAME

Courriel::Headers - The headers for an email part

VERSION

version 0.49

SYNOPSIS

    my $email = Courriel->parse( text => ... );
    my $headers = $email->headers;

    print "$_\n" for $headers->get('Received');

DESCRIPTION

This class represents the headers of an email.

Any sub part of an email can have its own headers, so every part has an associated object representing its headers. This class makes no distinction between top-level headers and headers for a sub part.

Each individual header name/value pair is represented internally by a Courriel::Header object. Some headers have their own special subclass. These are:

API

This class supports the following methods:

Courriel::Headers->parse( ... )

This method creates a new object by parsing a string. It accepts the following parameters:

  • text

    The text to parse. This can either be a plain scalar or a reference to a scalar. If you pass a reference, the underlying scalar may be modified.

Header parsing unfolds folded headers, and decodes any MIME-encoded values as described in RFC 2047. Parsing also decodes header attributes encoded as described in RFC 2231.

Courriel::Headers->new( headers => [ ... ] )

This method creates a new object. It accepts one parameter, headers, which should be an array reference of header names and values.

A given header key can appear multiple times.

This object does not (yet, perhaps) enforce RFC restrictions on repetition of certain headers.

Header order is preserved, per RFC 5322.

$headers->get($name)

Given a header name, this returns a list of the Courriel::Header objects found for the header. Each occurrence of the header is returned as a separate object.

$headers->get_values($name)

Given a header name, this returns a list of the string values found for the header. Each occurrence of the header is returned as a separate string.

$headers->add( $name => $value )

Given a header name and value, this adds the headers to the object. If any of the headers already have values in the object, then new values are added after the existing values, rather than at the end of headers.

The value can be provided as a string or a Courriel::Header object.

$headers->unshift( $name => $value )

This is like add(), but this pushes the headers onto the front of the internal headers array. This is useful if you are adding "Received" headers, which per RFC 5322, should always be added at the top of the headers.

The value can be provided as a string or a Courriel::Header object.

$headers->remove($name)

Given a header name, this removes all instances of that header from the object.

$headers->replace( $name => $value )

A shortcut for calling remove() and add().

The value can be provided as a string or a Courriel::Header object.

$headers->as_string( skip => ...., charset => ... )

This returns a string representing the headers in the object. The values will be folded and/or MIME-encoded as needed.

The skip parameter should be an array reference containing the name of headers that should be skipped. This parameter is optional, and the default is to include all headers.

The charset parameter specifies what character set to use for MIME-encoding non-ASCII values. This defaults to "utf8". The charset name must be one recognized by the Encode module.

MIME encoding is always done using the "B" (Base64) encoding, never the "Q" encoding.

$headers->stream_to( output => $output, skip => ...., charset => ... )

This method will send the stringified headers to the specified output.

See the as_string() method for documentation on the skip and charset parameters.

ROLES

This class does the Courriel::Role::Streams role.

SUPPORT

Bugs may be submitted at https://github.com/houseabsolute/Courriel/issues.

I am also usually active on IRC as 'autarch' on irc://irc.perl.org.

SOURCE

The source code repository for Courriel can be found at https://github.com/houseabsolute/Courriel.

AUTHOR

Dave Rolsky <autarch@urth.org>

COPYRIGHT AND LICENSE

This software is Copyright (c) 2021 by Dave Rolsky.

This is free software, licensed under:

  The Artistic License 2.0 (GPL Compatible)

The full text of the license can be found in the LICENSE file included with this distribution.