In some groups (particularly in archive groups), the From
header
isn’t very interesting, since all the articles there are written by
you. To display the information in the To
or Newsgroups
headers instead, you need to decide three things: What information to
gather; where to display it; and when to display it.
gnus-extra-headers
. This is a list of header symbols. For
instance:
(setq gnus-extra-headers '(To Newsgroups X-Newsreader))
This will result in Gnus trying to obtain these three headers, and storing it in header structures for later easy retrieval.
gnus-extra-header
function. Here’s a format line spec that will
access the X-Newsreader
header:
"%~(form (gnus-extra-header 'X-Newsreader))@"
gnus-ignored-from-addresses
variable says when the
‘%f’ summary line spec returns the To
, Newsreader
or From
header. The variable may be a regexp or a predicate
function. If this matches the contents of the From
header, the value of the To
or Newsreader
headers are
used instead.
To distinguish regular articles from those where the From
field
has been swapped, a string is prefixed to the To
or
Newsgroups
header in the summary line. By default the string is
‘-> ’ for To
and ‘=> ’ for Newsgroups
, you can
customize these strings with gnus-summary-to-prefix
and
gnus-summary-newsgroup-prefix
.
A related variable is nnmail-extra-headers
, which controls when
to include extra headers when generating overview (NOV) files.
If you have old overview files, you should regenerate them after
changing this variable, by entering the server buffer using ^,
and then g on the appropriate mail server (e.g., nnml) to cause
regeneration.
You also have to instruct Gnus to display the data by changing the
%n
spec to the %f
spec in the
gnus-summary-line-format
variable.
In summary, you’d typically put something like the following in ~/.gnus.el:
(setq gnus-extra-headers '(To Newsgroups)) (setq nnmail-extra-headers gnus-extra-headers) (setq gnus-summary-line-format "%U%R%z%I%(%[%4L: %-23,23f%]%) %s\n") (setq gnus-ignored-from-addresses "Your Name Here")
(The values listed above are the default values in Gnus. Alter them to fit your needs.)
A note for news server administrators, or for users who wish to try to convince their news server administrator to provide some additional support:
The above is mostly useful for mail groups, where you have control over the NOV files that are created. However, if you can persuade your nntp admin to add (in the usual implementation, notably INN):
Newsgroups:full
to the end of her overview.fmt file, then you can use that just as you would the extra headers from the mail groups. Otherwise, you have to disable fetching headers with ‘XOVER’:
(setq nntp-nov-is-evil t gnus-nov-is-evil t)
Be aware, though, that this will make entering an NNTP group much, much slower, so this is not recommended.
One particular scenario in which it can be desirable to not use
‘XOVER’ is for nnvirtual
groups in order to support
limiting by extra headers (e.g., by the newsgroup of its component
groups). Because group parameters are not inherited, a separate
select method for the component groups with the appropriate
nov-is-evil
set as a method variable is required.