Mail::Header - manipulate mail RFC822 compliant headers

    use Mail::Header;

    $head = new Mail::Header;
    $head = new Mail::Header \*STDIN;
    $head = new Mail::Header [<>], Modify => 0;

This package provides a class object which can be used for reading, creating, manipulating and writing RFC822 compliant headers.

new ( [ ARG ], [ OPTIONS ] )

CWARG 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. CWOPTIONS is a list of options given in the form of key-value pairs, just like a hash table. Valid options are

Modify

If this value is true then the headers will be re-formatted, otherwise the format of the header lines will remain unchanged.

MailFrom

This option specifies what to do when a header in the form `From ' is encountered. Valid values are CWIGNORE - ignore and discard the header, CWERROR - invoke an error (call die), CWCOERCE - rename them as Mail-From and CWKEEP - keep them.

FoldLength

The default length of line to be used when folding header lines

modify ( [ VALUE ] )

If CWVALUE is false then CWMail::Header will not do any automatic reformatting of the headers, other than to ensure that the line starts with the tags given.

mail_from ( OPTION )

CWOPTION specifies what to do when a CW`From ' line is encountered. Valid values are CWIGNORE - ignore and discard the header, CWERROR - invoke an error (call die), CWCOERCE - rename them as Mail-From and CWKEEP - keep them.

fold ( [ LENGTH ] )

Fold the header. If CWLENGTH is not given then CWMail::Header uses the following rules to determine what length to fold a line. The fold length for the tag that is begin processed The default fold length for the tag that is being processed The default fold length for the object

extract ( ARRAY_REF )

Extract a header from the given array. CWextract will modify this array. Returns the object that the method was called on.

read ( FD )

Read a header from the given file descriptor.

empty ()

Empty the CWMail::Header object of all lines.

header ( [ ARRAY_REF ] )

CWheader does multiple operations. First it will extract a header from the array, if given. It will the reformat the header, if reformatting is permitted, and finally return a reference to an array which contains the header in a printable form.

header_hashref ( [ HASH_REF ] )

As CWheader, but it will eventually set headers from a hash reference, and it will return the headers as a hash reference. The values in the hash might either be a scalar or an array reference, as an example:

    $hashref->{From}='Tobias Brox <tobix@cpan.org>';
    $hashref->{To}=['you@somewhere', 'me@localhost'];

add ( TAG, LINE [, INDEX ] )

Add a new line to the header. If CWTAG is undef the the tag will be extracted from the beginning of the given line. If CWINDEX 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.

replace ( TAG, LINE [, INDEX ] )

Replace a line in the header. If CWTAG is undef the the tag will be extracted from the beginning of the given line. If CWINDEX 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.

combine ( TAG [, WITH ] )

Combine all instances of CWTAG into one. The lines will be joined togther with CWWITH, 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.

get ( TAG [, INDEX ] )

Get the text form a line. If CWINDEX 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 CWget was called. In an array context a list of all the text from all the instances of CWTAG will be returned. In a scalar context the text for the first instance will be returned.

delete ( TAG [, INDEX ] )

Delete a tag from the header. If CWINDEX id given then the Nth instance of the tag will be removed. If CWINDEX is not given all instances of tag will be removed.

count ( TAG )

Returns the number of times the given atg appears in the header

print ( [ FD ] )

Print the header to the given file descriptor, or CWSTDOUT if no file descriptor is given.

as_string ()

Returns the header as a single string.

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 CWLENGTH is given it sets the default fold length for the current object. In the two argument form CWfold_length may be called as a static method, setting default fold lengths for tags that will be used by all CWMail::Header objects. See the CWfold method for a description on how CWMail::Header uses these values.

tags ()

Retruns 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.

dup ()

Create a duplicate of the current object.

cleanup ()

Remove any header line that, other than the tag, only contains whitespace

unfold ( [ TAG ] )

Unfold all instances of the given tag so that they do not spread across multiple lines. IF CWTAG is not given then all lines are unfolded.

Graham Barr. Maintained by Mark Overmeer <mailtools@overmeer.net>

Copyright (c) 2002-2003 Mark Overmeer, 1995-2001 Graham Barr. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.