Mail::Header(3) User Contributed Perl Documentation Mail::Header(3)
NAME
Mail::Header - manipulate MIME headers
INHERITANCE
SYNOPSIS
use Mail::Header;
my $head = Mail::Header->new;
my $head = Mail::Header->new( \*STDIN );
my $head = Mail::Header->new( [<>], Modify => 0);
DESCRIPTION
Read, write, create, and manipulate MIME headers, the leading part of
each modern e-mail message, but also used in other protocols like HTTP.
The fields are kept in Mail::Field objects.
Be aware that the header fields each have a name part, which shall be
treated case-insensitive, and a content part, which may be folded over
multiple lines.
Mail::Header does not always follow the RFCs strict enough, does not
help you with character encodings. It does not use weak references
where it could (because those did not exist when the module was
written) which costs some performance and make the implementation a
little more complicated. The Mail::Message::Head implementation is
much newer and therefore better.
METHODS
Constructors
$obj->dup
Create a duplicate of the current object.
$obj->new([ARG], [OPTIONS])
Mail::Header->new([ARG], [OPTIONS])
ARG may be either a file descriptor (reference to a GLOB) or a
reference to an array. If given the new object will be initialized
with headers either from the array of read from the file
descriptor.
OPTIONS is a list of options given in the form of key-value pairs,
just like a hash table. Valid options are
Option --Default
FoldLength 79
MailFrom 'KEEP'
Modify true
. FoldLength => INTEGER
The default length of line to be used when folding header
lines. See fold_length().
. MailFrom => 'IGNORE'|'COERCE'|'KEEP'|'ERROR'
See method mail_from().
. Modify => BOOLEAN
If this value is true then the headers will be re-formatted,
otherwise the format of the header lines will remain unchanged.
"Fake" constructors
Be warned that the next constructors all require an already created
header object, of which the original content will be destroyed.
$obj->empty
Empty an existing "Mail::Header" object of all lines.
$obj->extract(ARRAY)
Extract a header from the given array into an existing Mail::Header
object. "extract" will modify this array. Returns the object that
the method was called on.
$obj->header([ARRAY])
"header" does multiple operations. First it will extract a header
from the ARRAY, if given. It will then reformat the header (if
reformatting is permitted), and finally return a reference to an
array which contains the header in a printable form.
$obj->header_hashref([HASH])
As header(), but it will eventually set headers from a hash
reference, and it will return the headers as a hash reference.
example:
$fields->{From} = 'Tobias Brox <tobix@cpan.org>';
$fields->{To} = ['you@somewhere', 'me@localhost'];
$head->header_hashref($fields);
$obj->read(FILEHANDLE)
Read a header from the given file descriptor into an existing
Mail::Header object.
Accessors
$obj->fold_length([TAG], [LENGTH])
Set the default fold length for all tags or just one. With no
arguments the default fold length is returned. With two arguments
it sets the fold length for the given tag and returns the previous
value. If only "LENGTH" is given it sets the default fold length
for the current object.
In the two argument form "fold_length" may be called as a static
method, setting default fold lengths for tags that will be used by
all "Mail::Header" objects. See the "fold" method for a description
on how "Mail::Header" uses these values.
$obj->mail_from('IGNORE'|'COERCE'|'KEEP'|'ERROR')
This specifies what to do when a `From ' line is encountered.
Valid values are "IGNORE" - ignore and discard the header, "ERROR"
- invoke an error (call die), "COERCE" - rename them as Mail-From
and "KEEP" - keep them.
$obj->modify([VALUE])
If "VALUE" is false then "Mail::Header" will not do any automatic
reformatting of the headers, other than to ensure that the line
starts with the tags given.
Processing
$obj->add(TAG, LINE [, INDEX])
Add a new line to the header. If TAG is "undef" the the tag will be
extracted from the beginning of the given line. If INDEX is given,
the new line will be inserted into the header at the given point,
otherwise the new line will be appended to the end of the header.
$obj->as_string
Returns the header as a single string.
$obj->cleanup
Remove any header line that, other than the tag, only contains
whitespace
$obj->combine(TAG [, WITH])
Combine all instances of TAG into one. The lines will be joined
together WITH, or a single space if not given. The new item will be
positioned in the header where the first instance was, all other
instances of TAG will be removed.
$obj->count(TAG)
Returns the number of times the given atg appears in the header
$obj->delete(TAG [, INDEX ])
Delete a tag from the header. If an INDEX id is given, then the Nth
instance of the tag will be removed. If no INDEX is given, then all
instances of tag will be removed.
$obj->fold([LENGTH])
Fold the header. If LENGTH is not given, then "Mail::Header" uses
the following rules to determine what length to fold a line.
$obj->get(TAG [, INDEX])
Get the text from a line. If an INDEX is given, then the text of
the Nth instance will be returned. If it is not given the return
value depends on the context in which "get" was called. In an array
context a list of all the text from all the instances of the TAG
will be returned. In a scalar context the text for the first
instance will be returned.
The lines are unfolded, but still terminated with a new-line (see
"chomp")
$obj->print([FILEHANDLE])
Print the header to the given file descriptor, or "STDOUT" if no
file descriptor is given.
$obj->replace(TAG, LINE [, INDEX ])
Replace a line in the header. If TAG is "undef" the the tag will
be extracted from the beginning of the given line. If INDEX is
given the new line will replace the Nth instance of that tag,
otherwise the first instance of the tag is replaced. If the tag
does not appear in the header then a new line will be appended to
the header.
$obj->tags
Returns an array of all the tags that exist in the header. Each tag
will only appear in the list once. The order of the tags is not
specified.
$obj->unfold([TAG])
Unfold all instances of the given tag so that they do not spread
across multiple lines. If "TAG" is not given then all lines are
unfolded.
The unfolding process is wrong but (for compatibility reasons) will
not be repaired: only one blank at the start of the line should be
removed, not all of them.
SEE ALSO
This module is part of the MailTools distribution,
http://perl.overmeer.net/mailtools/.
AUTHORS
The MailTools bundle was developed by Graham Barr. Later, Mark
Overmeer took over maintenance without commitment to further
development.
Mail::Cap by Gisle Aas <aas@oslonett.no>. Mail::Field::AddrList by
Peter Orbaek <poe@cit.dk>. Mail::Mailer and Mail::Send by Tim Bunce
<Tim.Bunce@ig.co.uk>. For other contributors see ChangeLog.
LICENSE
Copyrights 1995-2000 Graham Barr <gbarr@pobox.com> and 2001-2007 Mark
Overmeer <perl@overmeer.net>.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself. See
http://www.perl.com/perl/misc/Artistic.html
perl v5.10.0 2008-07-29 Mail::Header(3)
Mac OS X 10.6 - Generated Thu Sep 17 20:13:34 CDT 2009