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   This file documents Gnus, the GNU Emacs newsreader.

   Copyright (C) 1995,96 Free Software Foundation, Inc.

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File: gnus.info,  Node: Customizing Threading,  Next: Thread Commands,  Up: Threading

Customizing Threading
---------------------

`gnus-show-threads'
     If this variable is `nil', no threading will be done, and all of
     the rest of the variables here will have no effect.  Turning
     threading off will speed group selection up a bit, but it is sure
     to make reading slower and more awkward.

`gnus-fetch-old-headers'
     If non-`nil', Gnus will attempt to build old threads by fetching
     more old headers--headers to articles that are marked as read.  If
     you would like to display as few summary lines as possible, but
     still connect as many loose threads as possible, you should set
     this variable to `some' or a number.  If you set it to a number,
     no more than that number of extra old headers will be fetched.  In
     either case, fetching old headers only works if the backend you
     are using carries overview files--this would normally be `nntp',
     `nnspool' and `nnml'.  Also remember that if the root of the
     thread has been expired by the server, there's not much Gnus can
     do about that.

`gnus-build-sparse-threads'
     Fetching old headers can be slow.  A low-rent similar effect can be
     gotten by setting this variable to `some'.  Gnus will then look at
     the complete `References' headers of all articles and try to string
     articles that belong in the same thread together.  This will leave
     "gaps" in the threading display where Gnus guesses that an article
     is missing from the thread.  (These gaps appear like normal summary
     lines.  If you select a gap, Gnus will try to fetch the article in
     question.)  If this variable is `t', Gnus will display all these
     "gaps" without regard for whether they are useful for completing
     the thread or not.  Finally, if this variable is `more', Gnus
     won't cut off sparse leaf nodes that don't lead anywhere.  This
     variable is `nil' by default.

`gnus-summary-gather-subject-limit'
     Loose threads are gathered by comparing subjects of articles.  If
     this variable is `nil', Gnus requires an exact match between the
     subjects of the loose threads before gathering them into one big
     super-thread.  This might be too strict a requirement, what with
     the presence of stupid newsreaders that chop off long subjects
     lines.  If you think so, set this variable to, say, 20 to require
     that only the first 20 characters of the subjects have to match.
     If you set this variable to a really low number, you'll find that
     Gnus will gather everything in sight into one thread, which isn't
     very helpful.

     If you set this variable to the special value `fuzzy', Gnus will
     use a fuzzy string comparison algorithm on the subjects.

`gnus-simplify-subject-fuzzy-regexp'
     This can either be a regular expression or list of regular
     expressions that match strings that will be removed from subjects
     if fuzzy subject simplification is used.

`gnus-simplify-ignored-prefixes'
     If you set `gnus-summary-gather-subject-limit' to something as low
     as 10, you might consider setting this variable to something
     sensible:

          (setq gnus-simplify-ignored-prefixes
                (concat
                 "\\`\\[?\\("
                 (mapconcat 'identity
                            '("looking"
                               "wanted" "followup" "summary\\( of\\)?"
                               "help" "query" "problem" "question"
                               "answer" "reference" "announce"
                               "How can I" "How to" "Comparison of"
                               ;; ...
                               )
                            "\\|")
                            "\\)\\s *\\("
                            (mapconcat 'identity
                                       '("for" "for reference" "with" "about")
                                       "\\|")
                            "\\)?\\]?:?[ \t]*"))

     All words that match this regexp will be removed before comparing
     two subjects.

`gnus-summary-gather-exclude-subject'
     Since loose thread gathering is done on subjects only, that might
     lead to many false hits, especially with certain common subjects
     like `' and `(none)'.  To make the situation slightly better, you
     can use the regexp `gnus-summary-gather-exclude-subject' to say
     what subjects should be excluded from the gathering process.  The
     default is `^ *$\\|^(none)$'.

`gnus-summary-thread-gathering-function'
     Gnus gathers threads by looking at `Subject' headers.  This means
     that totally unrelated articles may end up in the same "thread",
     which is confusing.  An alternate approach is to look at all the
     `Message-ID's in all the `References' headers to find matches.
     This will ensure that no gathered threads ever includes unrelated
     articles, but it's also means that people who have posted with
     broken newsreaders won't be gathered properly.  The choice is
     yours--plague or cholera:

    `gnus-gather-threads-by-subject'
          This function is the default gathering function and looks at
          `Subject's exclusively.

    `gnus-gather-threads-by-references'
          This function looks at `References' headers exclusively.

     If you want to test gathering by `References', you could say
     something like:

          (setq gnus-summary-thread-gathering-function
                'gnus-gather-threads-by-references)

`gnus-summary-make-false-root'
     If non-`nil', Gnus will gather all loose subtrees into one big tree
     and create a dummy root at the top.  (Wait a minute.  Root at the
     top?  Yup.)  Loose subtrees occur when the real root has expired,
     or you've read or killed the root in a previous session.

     When there is no real root of a thread, Gnus will have to fudge
     something.  This variable says what fudging method Gnus should use.
     There are four possible values:

    `adopt'
          Gnus will make the first of the orphaned articles the parent.
          This parent will adopt all the other articles.  The adopted
          articles will be marked as such by pointy brackets (`<>')
          instead of the standard square brackets (`[]').  This is the
          default method.

    `dummy'
          Gnus will create a dummy summary line that will pretend to be
          the parent.  This dummy line does not correspond to any real
          article, so selecting it will just select the first real
          article after the dummy article.
          `gnus-summary-dummy-line-format' is used to specify the
          format of the dummy roots.  It accepts only one format spec:
          `S', which is the subject of the article.  *Note Formatting
          Variables::.

    `empty'
          Gnus won't actually make any article the parent, but simply
          leave the subject field of all orphans except the first
          empty.  (Actually, it will use `gnus-summary-same-subject' as
          the subject (*note Summary Buffer Format::.).)

    `none'
          Don't make any article parent at all.  Just gather the
          threads and display them after one another.

    `nil'
          Don't gather loose threads.

`gnus-thread-hide-subtree'
     If non-`nil', all threads will be hidden when the summary buffer is
     generated.

`gnus-thread-hide-killed'
     if you kill a thread and this variable is non-`nil', the subtree
     will be hidden.

`gnus-thread-ignore-subject'
     Sometimes somebody changes the subject in the middle of a thread.
     If this variable is non-`nil', the subject change is ignored.  If
     it is `nil', which is the default, a change in the subject will
     result in a new thread.

`gnus-thread-indent-level'
     This is a number that says how much each sub-thread should be
     indented.  The default is `4'.


File: gnus.info,  Node: Thread Commands,  Prev: Customizing Threading,  Up: Threading

Thread Commands
---------------

`T k'
`M-C-k'
     Mark all articles in the current sub-thread as read
     (`gnus-summary-kill-thread').  If the prefix argument is positive,
     remove all marks instead.  If the prefix argument is negative, tick
     articles instead.

`T l'
`M-C-l'
     Lower the score of the current thread
     (`gnus-summary-lower-thread').

`T i'
     Increase the score of the current thread
     (`gnus-summary-raise-thread').

`T #'
     Set the process mark on the current thread (`gnus-uu-mark-thread').

`T M-#'
     Remove the process mark from the current thread
     (`gnus-uu-unmark-thread').

`T T'
     Toggle threading (`gnus-summary-toggle-threads').

`T s'
     Expose the thread hidden under the current article, if any
     (`gnus-summary-show-thread').

`T h'
     Hide the current (sub)thread (`gnus-summary-hide-thread').

`T S'
     Expose all hidden threads (`gnus-summary-show-all-threads').

`T H'
     Hide all threads (`gnus-summary-hide-all-threads').

`T t'
     Re-thread the thread the current article is part of
     (`gnus-summary-rethread-current').  This works even when the
     summary buffer is otherwise unthreaded.

`T ^'
     Make the current article the child of the marked (or previous)
     article (`gnus-summary-reparent-thread'.

   The following commands are thread movement commands.  They all
understand the numeric prefix.

`T n'
     Go to the next thread (`gnus-summary-next-thread').

`T p'
     Go to the previous thread (`gnus-summary-prev-thread').

`T d'
     Descend the thread (`gnus-summary-down-thread').

`T u'
     Ascend the thread (`gnus-summary-up-thread').

`T o'
     Go to the top of the thread (`gnus-summary-top-thread').

   If you ignore subject while threading, you'll naturally end up with
threads that have several different subjects in them.  If you then issue
a command like `T k' (`gnus-summary-kill-thread') you might not wish to
kill the entire thread, but just those parts of the thread that have
the same subject as the current article.  If you like this idea, you
can fiddle with `gnus-thread-operation-ignore-subject'.  If is is
non-`nil' (which it is by default), subjects will be ignored when doing
thread commands.  If this variable is `nil', articles in the same
thread with different subjects will not be included in the operation in
question.  If this variable is `fuzzy', only articles that have
subjects that are fuzzily equal will be included.


File: gnus.info,  Node: Sorting,  Next: Asynchronous Fetching,  Prev: Threading,  Up: The Summary Buffer

Sorting
=======

   If you are using a threaded summary display, you can sort the
threads by setting `gnus-thread-sort-functions', which is a list of
functions.  By default, sorting is done on article numbers.  Ready-made
sorting predicate functions include `gnus-thread-sort-by-number',
`gnus-thread-sort-by-author', `gnus-thread-sort-by-subject',
`gnus-thread-sort-by-date', `gnus-thread-sort-by-score', and
`gnus-thread-sort-by-total-score'.

   Each function takes two threads and return non-`nil' if the first
thread should be sorted before the other.  Note that sorting really is
normally done by looking only at the roots of each thread.  If you use
more than one function, the primary sort key should be the last function
in the list.  You should probably always include
`gnus-thread-sort-by-number' in the list of sorting
functions--preferably first.  This will ensure that threads that are
equal with respect to the other sort criteria will be displayed in
ascending article order.

   If you would like to sort by score, then by subject, and finally by
number, you could do something like:

     (setq gnus-thread-sort-functions
           '(gnus-thread-sort-by-number
             gnus-thread-sort-by-subject
             gnus-thread-sort-by-score))

   The threads that have highest score will be displayed first in the
summary buffer.  When threads have the same score, they will be sorted
alphabetically.  The threads that have the same score and the same
subject will be sorted by number, which is (normally) the sequence in
which the articles arrived.

   If you want to sort by score and then reverse arrival order, you
could say something like:

     (setq gnus-thread-sort-functions
           '((lambda (t1 t2)
               (not (gnus-thread-sort-by-number t1 t2)))
             gnus-thread-sort-by-score))

   The function in the `gnus-thread-score-function' variable (default
`+') is used for calculating the total score of a thread.  Useful
functions might be `max', `min', or squared means, or whatever tickles
your fancy.

   If you are using an unthreaded display for some strange reason or
other, you have to fiddle with the `gnus-article-sort-functions'
variable.  It is very similar to the `gnus-thread-sort-functions',
except that is uses slightly different functions for article
comparison.  Available sorting predicate functions are
`gnus-article-sort-by-number', `gnus-article-sort-by-author',
`gnus-article-sort-by-subject', `gnus-article-sort-by-date', and
`gnus-article-sort-by-score'.

   If you want to sort an unthreaded summary display by subject, you
could say something like:

     (setq gnus-article-sort-functions
           '(gnus-article-sort-by-number
             gnus-article-sort-by-subject))


File: gnus.info,  Node: Asynchronous Fetching,  Next: Article Caching,  Prev: Sorting,  Up: The Summary Buffer

Asynchronous Article Fetching
=============================

   If you read your news from an NNTP server that's far away, the
network latencies may make reading articles a chore.  You have to wait
for a while after pressing `n' to go to the next article before the
article appears.  Why can't Gnus just go ahead and fetch the article
while you are reading the previous one? Why not, indeed.

   First, some caveats.  There are some pitfalls to using asynchronous
article fetching, especially the way Gnus does it.

   Let's say you are reading article 1, which is short, and article 2 is
quite long, and you are not interested in reading that.  Gnus does not
know this, so it goes ahead and fetches article 2.  You decide to read
article 3, but since Gnus is in the process of fetching article 2, the
connection is blocked.

   To avoid these situations, Gnus will open two (count 'em two)
connections to the server.  Some people may think this isn't a very nice
thing to do, but I don't see any real alternatives.  Setting up that
extra connection takes some time, so Gnus startup will be slower.

   Gnus will fetch more articles than you will read.  This will mean
that the link between your machine and the NNTP server will become more
loaded than if you didn't use article pre-fetch.  The server itself will
also become more loaded--both with the extra article requests, and the
extra connection.

   Ok, so now you know that you shouldn't really use this thing...
unless you really want to.

   Here's how:  Set `gnus-asynchronous' to `t'.  The rest should happen
automatically.

   You can control how many articles that are to be pre-fetched by
setting `nntp-async-number'.  This is five by default, which means that
when you read an article in the group, `nntp' will pre-fetch the next
five articles.  If this variable is `t', `nntp' will pre-fetch all the
articles that it can without bound.  If it is `nil', no pre-fetching
will be made.

   You may wish to create some sort of scheme for choosing which
articles that `nntp' should consider as candidates for pre-fetching.
For instance, you may wish to pre-fetch all articles with high scores,
and not pre-fetch low-scored articles.  You can do that by setting the
`gnus-asynchronous-article-function', which will be called with an
alist where the keys are the article numbers.  Your function should
return an alist where the articles you are not interested in have been
removed.  You could also do sorting on article score and the like.


File: gnus.info,  Node: Article Caching,  Next: Persistent Articles,  Prev: Asynchronous Fetching,  Up: The Summary Buffer

Article Caching
===============

   If you have an *extremely* slow NNTP connection, you may consider
turning article caching on.  Each article will then be stored locally
under your home directory.  As you may surmise, this could potentially
use *huge* amounts of disk space, as well as eat up all your inodes so
fast it will make your head swim.  In vodka.

   Used carefully, though, it could be just an easier way to save
articles.

   To turn caching on, set `gnus-use-cache' to `t'.  By default, all
articles that are ticked or marked as dormant will then be copied over
to your local cache (`gnus-cache-directory').  Whether this cache is
flat or hierarchal is controlled by the `gnus-use-long-file-name'
variable, as usual.

   When re-select a ticked or dormant article, it will be fetched from
the cache instead of from the server.  As articles in your cache will
never expire, this might serve as a method of saving articles while
still keeping them where they belong.  Just mark all articles you want
to save as dormant, and don't worry.

   When an article is marked as read, is it removed from the cache.

   The entering/removal of articles from the cache is controlled by the
`gnus-cache-enter-articles' and `gnus-cache-remove-articles' variables.
Both are lists of symbols.  The first is `(ticked dormant)' by
default, meaning that ticked and dormant articles will be put in the
cache.  The latter is `(read)' by default, meaning that articles that
are marked as read are removed from the cache.  Possibly symbols in
these two lists are `ticked', `dormant', `unread' and `read'.

   So where does the massive article-fetching and storing come into the
picture?  The `gnus-jog-cache' command will go through all subscribed
newsgroups, request all unread articles, and store them in the cache.
You should only ever, ever ever ever, use this command if 1) your
connection to the NNTP server is really, really, really slow and 2) you
have a really, really, really huge disk.  Seriously.

   It is likely that you do not want caching on some groups.  For
instance, if your `nnml' mail is located under your home directory, it
makes no sense to cache it somewhere else under your home directory.
Unless you feel that it's neat to use twice as much space.  To limit
the caching, you could set the `gnus-uncacheable-groups' regexp to
`^nnml', for instance.  This variable is `nil' by default.

   The cache stores information on what articles it contains in its
active file (`gnus-cache-active-file').  If this file (or any other
parts of the cache) becomes all messed up for some reason or other, Gnus
offers two functions that will try to set things right.  `M-x
gnus-cache-generate-nov-databases' will (re)build all the NOV files,
and `gnus-cache-generate-active' will (re)generate the active file.


File: gnus.info,  Node: Persistent Articles,  Next: Article Backlog,  Prev: Article Caching,  Up: The Summary Buffer

Persistent Articles
===================

   Closely related to article caching, we have "persistent articles".
In fact, it's just a different way of looking at caching, and much more
useful in my opinion.

   Say you're reading a newsgroup, and you happen on to some valuable
gem that you want to keep and treasure forever.  You'd normally just
save it (using one of the many saving commands) in some file.  The
problem with that is that it's just, well, yucky.  Ideally you'd prefer
just having the article remain in the group where you found it forever;
untouched by the expiry going on at the news server.

   This is what a "persistent article" is--an article that just won't
be deleted.  It's implemented using the normal cache functions, but you
use two explicit commands for managing persistent articles:

`*'
     Make the current article persistent (`gnus-cache-enter-article').

`M-*'
     Remove the current article from the persistent articles
     (`gnus-cache-remove-article').  This will normally delete the
     article.

   Both these commands understand the process/prefix convention.

   To avoid having all ticked articles (and stuff) entered into the
cache, you should set `gnus-use-cache' to `passive' if you're just
interested in persistent articles:

     (setq gnus-use-cache 'passive)


File: gnus.info,  Node: Article Backlog,  Next: Saving Articles,  Prev: Persistent Articles,  Up: The Summary Buffer

Article Backlog
===============

   If you have a slow connection, but the idea of using caching seems
unappealing to you (and it is, really), you can help the situation some
by switching on the "backlog".  This is where Gnus will buffer already
read articles so that it doesn't have to re-fetch articles you've
already read.  This only helps if you are in the habit of re-selecting
articles you've recently read, of course.  If you never do that,
turning the backlog on will slow Gnus down a little bit, and increase
memory usage some.

   If you set `gnus-keep-backlog' to a number N, Gnus will store at
most N old articles in a buffer for later re-fetching.  If this
variable is non-`nil' and is not a number, Gnus will store *all* read
articles, which means that your Emacs will grow without bound before
exploding and taking your machine down with you.  I put that in there
just to keep y'all on your toes.

   This variable is `nil' by default.


File: gnus.info,  Node: Saving Articles,  Next: Decoding Articles,  Prev: Article Backlog,  Up: The Summary Buffer

Saving Articles
===============

   Gnus can save articles in a number of ways.  Below is the
documentation for saving articles in a fairly straight-forward fashion
(i.e., little processing of the article is done before it is saved).
For a different approach (uudecoding, unsharing) you should use
`gnus-uu' (*note Decoding Articles::.).

   If `gnus-save-all-headers' is non-`nil', Gnus will not delete
unwanted headers before saving the article.

   If the preceding variable is `nil', all headers that match the
`gnus-saved-headers' regexp will be kept, while the rest will be
deleted before saving.

`O o'
`o'
     Save the current article using the default article saver
     (`gnus-summary-save-article').

`O m'
     Save the current article in mail format
     (`gnus-summary-save-article-mail').

`O r'
     Save the current article in rmail format
     (`gnus-summary-save-article-rmail').

`O f'
     Save the current article in plain file format
     (`gnus-summary-save-article-file').

`O b'
     Save the current article body in plain file format
     (`gnus-summary-save-article-body-file').

`O h'
     Save the current article in mh folder format
     (`gnus-summary-save-article-folder').

`O v'
     Save the current article in a VM folder
     (`gnus-summary-save-article-vm').

`O p'
     Save the current article in a pipe.  Uhm, like, what I mean
     is--Pipe the current article to a process
     (`gnus-summary-pipe-output').

   All these commands use the process/prefix convention (*note
Process/Prefix::.).  If you save bunches of articles using these
functions, you might get tired of being prompted for files to save each
and every article in.  The prompting action is controlled by the
`gnus-prompt-before-saving' variable, which is `always' by default,
giving you that excessive prompting action you know and loathe.  If you
set this variable to `t' instead, you'll be prompted just once for each
series of articles you save.  If you like to really have Gnus do all
your thinking for you, you can even set this variable to `nil', which
means that you will never be prompted for files to save articles in.
Gnus will simply save all the articles in the default files.

   You can customize the `gnus-default-article-saver' variable to make
Gnus do what you want it to.  You can use any of the four ready-made
functions below, or you can create your own.

`gnus-summary-save-in-rmail'
     This is the default format, "babyl".  Uses the function in the
     `gnus-rmail-save-name' variable to get a file name to save the
     article in.  The default is `gnus-plain-save-name'.

`gnus-summary-save-in-mail'
     Save in a Unix mail (mbox) file.  Uses the function in the
     `gnus-mail-save-name' variable to get a file name to save the
     article in.  The default is `gnus-plain-save-name'.

`gnus-summary-save-in-file'
     Append the article straight to an ordinary file.  Uses the
     function in the `gnus-file-save-name' variable to get a file name
     to save the article in.  The default is `gnus-numeric-save-name'.

`gnus-summary-save-body-in-file'
     Append the article body to an ordinary file.  Uses the function in
     the `gnus-file-save-name' variable to get a file name to save the
     article in.  The default is `gnus-numeric-save-name'.

`gnus-summary-save-in-folder'
     Save the article to an MH folder using `rcvstore' from the MH
     library.  Uses the function in the `gnus-folder-save-name' variable
     to get a file name to save the article in.  The default is
     `gnus-folder-save-name', but you can also use
     `gnus-Folder-save-name'.  The former creates capitalized names, and
     the latter does not.

`gnus-summary-save-in-vm'
     Save the article in a VM folder.  You have to have the VM mail
     reader to use this setting.

   All of these functions, except for the last one, will save the
article in the `gnus-article-save-directory', which is initialized from
the `SAVEDIR' environment variable.  This is `~/News/' by default.

   As you can see above, the functions use different functions to find a
suitable name of a file to save the article in.  Below is a list of
available functions that generate names:

`gnus-Numeric-save-name'
     Generates file names that look like `~/News/Alt.andrea-dworkin/45'.

`gnus-numeric-save-name'
     Generates file names that look like `~/News/alt.andrea-dworkin/45'.

`gnus-Plain-save-name'
     Generates file names that look like `~/News/Alt.andrea-dworkin'.

`gnus-plain-save-name'
     Generates file names that look like `~/News/alt.andrea-dworkin'.

   You can have Gnus suggest where to save articles by plonking a
regexp into the `gnus-split-methods' alist.  For instance, if you would
like to save articles related to Gnus in the file `gnus-stuff', and
articles related to VM in `vm-stuff', you could set this variable to
something like:

     (("^Subject:.*gnus\\|^Newsgroups:.*gnus" "gnus-stuff")
      ("^Subject:.*vm\\|^Xref:.*vm" "vm-stuff")
      (my-choosing-function "../other-dir/my-stuff")
      ((equal gnus-newsgroup-name "mail.misc") "mail-stuff"))

   We see that this is a list where each element is a list that has two
elements--the "match" and the "file".  The match can either be a string
(in which case it is used as a regexp to match on the article head); it
can be a symbol (which will be called as a function with the group name
as a parameter); or it can be a list (which will be `eval'ed).  If any
of these actions have a non-`nil' result, the "file" will be used as a
default prompt.  In addition, the result of the operation itself will
be used if the function or form called returns a string or a list of
strings.

   You basically end up with a list of file names that might be used
when saving the current article.  (All "matches" will be used.)  You
will then be prompted for what you really want to use as a name, with
file name completion over the results from applying this variable.

   This variable is `((gnus-article-archive-name))' by default, which
means that Gnus will look at the articles it saves for an
`Archive-name' line and use that as a suggestion for the file name.

   Finally, you have the `gnus-use-long-file-name' variable.  If it is
`nil', all the preceding functions will replace all periods (`.') in
the group names with slashes (`/')--which means that the functions will
generate hierarchies of directories instead of having all the files in
the toplevel directory (`~/News/alt/andrea-dworkin' instead of
`~/News/alt.andrea-dworkin'.)  This variable is `t' by default on most
systems.  However, for historical reasons, this is `nil' on Xenix and
usg-unix-v machines by default.

   This function also affects kill and score file names.  If this
variable is a list, and the list contains the element `not-score', long
file names will not be used for score files, if it contains the element
`not-save', long file names will not be used for saving, and if it
contains the element `not-kill', long file names will not be used for
kill files.

   If you'd like to save articles in a hierarchy that looks something
like a spool, you could

     (setq gnus-use-long-file-name '(not-save)) ; to get a hierarchy
     (setq gnus-default-article-save 'gnus-summary-save-in-file) ; no encoding

   Then just save with `o'.  You'd then read this hierarchy with
ephemeral `nneething' groups--`G D' in the group buffer, and the
toplevel directory as the argument (`~/News/').  Then just walk around
to the groups/directories with `nneething'.


File: gnus.info,  Node: Decoding Articles,  Next: Article Treatment,  Prev: Saving Articles,  Up: The Summary Buffer

Decoding Articles
=================

   Sometime users post articles (or series of articles) that have been
encoded in some way or other.  Gnus can decode them for you.

* Menu:

* Uuencoded Articles::    Uudecode articles.
* Shared Articles::       Unshar articles.
* PostScript Files::      Split PostScript.
* Decoding Variables::    Variables for a happy decoding.
* Viewing Files::         You want to look at the result of the decoding?

   All these functions use the process/prefix convention (*note
Process/Prefix::.) for finding out what articles to work on, with the
extension that a "single article" means "a single series".  Gnus can
find out by itself what articles belong to a series, decode all the
articles and unpack/view/save the resulting file(s).

   Gnus guesses what articles are in the series according to the
following simplish rule: The subjects must be (nearly) identical,
except for the last two numbers of the line.  (Spaces are largely
ignored, however.)

   For example: If you choose a subject called `cat.gif (2/3)', Gnus
will find all the articles that match the regexp `^cat.gif
([0-9]+/[0-9]+).*$'.

   Subjects that are nonstandard, like `cat.gif (2/3) Part 6 of a
series', will not be properly recognized by any of the automatic viewing
commands, and you have to mark the articles manually with `#'.


File: gnus.info,  Node: Uuencoded Articles,  Next: Shared Articles,  Up: Decoding Articles

Uuencoded Articles
------------------

`X u'
     Uudecodes the current series (`gnus-uu-decode-uu').

`X U'
     Uudecodes and saves the current series
     (`gnus-uu-decode-uu-and-save').

`X v u'
     Uudecodes and views the current series (`gnus-uu-decode-uu-view').

`X v U'
     Uudecodes, views and saves the current series
     (`gnus-uu-decode-uu-and-save-view').

   Remember that these all react to the presence of articles marked with
the process mark.  If, for instance, you'd like to decode and save an
entire newsgroup, you'd typically do `M P a' (`gnus-uu-mark-all') and
then `X U' (`gnus-uu-decode-uu-and-save').

   All this is very much different from how `gnus-uu' worked with GNUS
4.1, where you had explicit keystrokes for everything under the sun.
This version of `gnus-uu' generally assumes that you mark articles in
some way (*note Setting Process Marks::.) and then press `X u'.

   Note: When trying to decode articles that have names matching
`gnus-uu-notify-files', which is hard-coded to
`[Cc][Ii][Nn][Dd][Yy][0-9]+.\\(gif\\|jpg\\)', `gnus-uu' will
automatically post an article on `comp.unix.wizards' saying that you
have just viewed the file in question.  This feature can't be turned
off.


File: gnus.info,  Node: Shared Articles,  Next: PostScript Files,  Prev: Uuencoded Articles,  Up: Decoding Articles

Shared Articles
---------------

`X s'
     Unshars the current series (`gnus-uu-decode-unshar').

`X S'
     Unshars and saves the current series
     (`gnus-uu-decode-unshar-and-save').

`X v s'
     Unshars and views the current series
     (`gnus-uu-decode-unshar-view').

`X v S'
     Unshars, views and saves the current series
     (`gnus-uu-decode-unshar-and-save-view').


File: gnus.info,  Node: PostScript Files,  Next: Decoding Variables,  Prev: Shared Articles,  Up: Decoding Articles

PostScript Files
----------------

`X p'
     Unpack the current PostScript series (`gnus-uu-decode-postscript').

`X P'
     Unpack and save the current PostScript series
     (`gnus-uu-decode-postscript-and-save').

`X v p'
     View the current PostScript series
     (`gnus-uu-decode-postscript-view').

`X v P'
     View and save the current PostScript series
     (`gnus-uu-decode-postscript-and-save-view').


File: gnus.info,  Node: Decoding Variables,  Next: Viewing Files,  Prev: PostScript Files,  Up: Decoding Articles

Decoding Variables
------------------

   Adjective, not verb.

* Menu:

* Rule Variables::          Variables that say how a file is to be viewed.
* Other Decode Variables::  Other decode variables.
* Uuencoding and Posting::  Variables for customizing uuencoding.


File: gnus.info,  Node: Rule Variables,  Next: Other Decode Variables,  Up: Decoding Variables

Rule Variables
..............

   Gnus uses "rule variables" to decide how to view a file.  All these
variables are on the form

           (list '(regexp1 command2)
                 '(regexp2 command2)
                 ...)

`gnus-uu-user-view-rules'
     This variable is consulted first when viewing files.  If you wish
     to use, for instance, `sox' to convert an `.au' sound file, you
     could say something like:
                 (setq gnus-uu-user-view-rules
                   (list '(\"\\\\.au$\" \"sox %s -t .aiff > /dev/audio\")))

`gnus-uu-user-view-rules-end'
     This variable is consulted if Gnus couldn't make any matches from
     the user and default view rules.

`gnus-uu-user-archive-rules'
     This variable can be used to say what commands should be used to
     unpack archives.


File: gnus.info,  Node: Other Decode Variables,  Next: Uuencoding and Posting,  Prev: Rule Variables,  Up: Decoding Variables

Other Decode Variables
......................

`gnus-uu-grabbed-file-functions'
     All functions in this list will be called right each file has been
     successfully decoded--so that you can move or view files right
     away, and don't have to wait for all files to be decoded before
     you can do anything.  Ready-made functions you can put in this
     list are:

    `gnus-uu-grab-view'
          View the file.

    `gnus-uu-grab-move'
          Move the file (if you're using a saving function.)

`gnus-uu-ignore-files-by-name'
     Files with name matching this regular expression won't be viewed.

`gnus-uu-ignore-files-by-type'
     Files with a MIME type matching this variable won't be viewed.
     Note that Gnus tries to guess what type the file is based on the
     name.  `gnus-uu' is not a MIME package (yet), so this is slightly
     kludgey.

`gnus-uu-tmp-dir'
     Where `gnus-uu' does its work.

`gnus-uu-do-not-unpack-archives'
     Non-`nil' means that `gnus-uu' won't peek inside archives looking
     for files to display.

`gnus-uu-view-and-save'
     Non-`nil' means that the user will always be asked to save a file
     after viewing it.

`gnus-uu-ignore-default-view-rules'
     Non-`nil' means that `gnus-uu' will ignore the default viewing
     rules.

`gnus-uu-ignore-default-archive-rules'
     Non-`nil' means that `gnus-uu' will ignore the default archive
     unpacking commands.

`gnus-uu-kill-carriage-return'
     Non-`nil' means that `gnus-uu' will strip all carriage returns
     from articles.

`gnus-uu-unmark-articles-not-decoded'
     Non-`nil' means that `gnus-uu' will mark articles that were
     unsuccessfully decoded as unread.

`gnus-uu-correct-stripped-uucode'
     Non-`nil' means that `gnus-uu' will *try* to fix uuencoded files
     that have had trailing spaces deleted.

`gnus-uu-view-with-metamail'
     Non-`nil' means that `gnus-uu' will ignore the viewing commands
     defined by the rule variables and just fudge a MIME content type
     based on the file name.  The result will be fed to `metamail' for
     viewing.

`gnus-uu-save-in-digest'
     Non-`nil' means that `gnus-uu', when asked to save without
     decoding, will save in digests.  If this variable is `nil',
     `gnus-uu' will just save everything in a file without any
     embellishments.  The digesting almost conforms to RFC1153--no easy
     way to specify any meaningful volume and issue numbers were found,
     so I simply dropped them.


File: gnus.info,  Node: Uuencoding and Posting,  Prev: Other Decode Variables,  Up: Decoding Variables

Uuencoding and Posting
......................

`gnus-uu-post-include-before-composing'
     Non-`nil' means that `gnus-uu' will ask for a file to encode
     before you compose the article.  If this variable is `t', you can
     either include an encoded file with `C-c C-i' or have one included
     for you when you post the article.

`gnus-uu-post-length'
     Maximum length of an article.  The encoded file will be split into
     how many articles it takes to post the entire file.

`gnus-uu-post-threaded'
     Non-`nil' means that `gnus-uu' will post the encoded file in a
     thread.  This may not be smart, as no other decoder I have seen
     are able to follow threads when collecting uuencoded articles.
     (Well, I have seen one package that does that--`gnus-uu', but
     somehow, I don't think that counts...) Default is `nil'.

`gnus-uu-post-separate-description'
     Non-`nil' means that the description will be posted in a separate
     article.  The first article will typically be numbered (0/x).  If
     this variable is `nil', the description the user enters will be
     included at the beginning of the first article, which will be
     numbered (1/x).  Default is `t'.


File: gnus.info,  Node: Viewing Files,  Prev: Decoding Variables,  Up: Decoding Articles

Viewing Files
-------------

   After decoding, if the file is some sort of archive, Gnus will
attempt to unpack the archive and see if any of the files in the
archive can be viewed.  For instance, if you have a gzipped tar file
`pics.tar.gz' containing the files `pic1.jpg' and `pic2.gif', Gnus will
uncompress and de-tar the main file, and then view the two pictures.
This unpacking process is recursive, so if the archive contains archives
of archives, it'll all be unpacked.

   Finally, Gnus will normally insert a "pseudo-article" for each
extracted file into the summary buffer.  If you go to these "articles",
you will be prompted for a command to run (usually Gnus will make a
suggestion), and then the command will be run.

   If `gnus-view-pseudo-asynchronously' is `nil', Emacs will wait until
the viewing is done before proceeding.

   If `gnus-view-pseudos' is `automatic', Gnus will not insert the
pseudo-articles into the summary buffer, but view them immediately.  If
this variable is `not-confirm', the user won't even be asked for a
confirmation before viewing is done.

   If `gnus-view-pseudos-separately' is non-`nil', one pseudo-article
will be created for each file to be viewed.  If `nil', all files that
use the same viewing command will be given as a list of parameters to
that command.

   If `gnus-insert-pseudo-articles' is non-`nil', insert
pseudo-articles when decoding.  It is `t' by default.

   So; there you are, reading your *pseudo-articles* in your *virtual
newsgroup* from the *virtual server*; and you think: Why isn't anything
real anymore? How did we get here?


File: gnus.info,  Node: Article Treatment,  Next: Summary Sorting,  Prev: Decoding Articles,  Up: The Summary Buffer

Article Treatment
=================

   Reading through this huge manual, you may have quite forgotten that
the object of newsreaders are to actually, like, read what people have
written.  Reading articles.  Unfortunately, people are quite bad at
writing, so there are tons of functions and variables to make reading
these articles easier.

* Menu:

* Article Highlighting::    You want to make the article look like fruit salad.
* Article Hiding::          You also want to make certain info go away.
* Article Washing::         Lots of way-neat functions to make life better.
* Article Buttons::         Click on URLs, Message-IDs, addresses and the like.
* Article Date::            Grumble, UT!


File: gnus.info,  Node: Article Highlighting,  Next: Article Hiding,  Up: Article Treatment

Article Highlighting
--------------------

   Not only do you want your article buffer to look like fruit salad,
but you want it to look like technicolor fruit salad.

`W H a'
     Highlight the current article (`gnus-article-highlight').

`W H h'
     Highlight the headers (`gnus-article-highlight-headers').  The
     highlighting will be done according to the `gnus-header-face-alist'
     variable, which is a list where each element has the form (REGEXP
     NAME CONTENT).  REGEXP is a regular expression for matching the
     header, NAME is the face used for highlighting the header name and
     CONTENT is the face for highlighting the header value.  The first
     match made will be used.  Note that REGEXP shouldn't have `^'
     prepended--Gnus will add one.

`W H c'
     Highlight cited text (`gnus-article-highlight-citation').

     Some variables to customize the citation highlights:

    `gnus-cite-parse-max-size'
          If the article size if bigger than this variable (which is
          25000 by default), no citation highlighting will be performed.

    `gnus-cite-prefix-regexp'
          Regexp matching the longest possible citation prefix on a
          line.

    `gnus-cite-max-prefix'
          Maximum possible length for a citation prefix (default 20).

    `gnus-cite-face-list'
          List of faces used for highlighting citations.  When there
          are citations from multiple articles in the same message,
          Gnus will try to give each citation from each article its own
          face.  This should make it easier to see who wrote what.

    `gnus-supercite-regexp'
          Regexp matching normal Supercite attribution lines.

    `gnus-supercite-secondary-regexp'
          Regexp matching mangled Supercite attribution lines.

    `gnus-cite-minimum-match-count'
          Minimum number of identical prefixes we have to see before we
          believe that it's a citation.

    `gnus-cite-attribution-prefix'
          Regexp matching the beginning of an attribution line.

    `gnus-cite-attribution-suffix'
          Regexp matching the end of an attribution line.

    `gnus-cite-attribution-face'
          Face used for attribution lines.  It is merged with the face
          for the cited text belonging to the attribution.

`W H s'
     Highlight the signature (`gnus-article-highlight-signature').
     Everything after `gnus-signature-separator' in an article will be
     considered a signature and will be highlighted with
     `gnus-signature-face', which is `italic' by default.


File: gnus.info,  Node: Article Hiding,  Next: Article Washing,  Prev: Article Highlighting,  Up: Article Treatment

Article Hiding
--------------

   Or rather, hiding certain things in each article.  There usually is
much too much cruft in most articles.

`W W a'
     Do maximum hiding on the summary buffer (`gnus-article-hide').

`W W h'
     Hide headers (`gnus-article-hide-headers').  *Note Hiding
     Headers::.

`W W b'
     Hide headers that aren't particularly interesting
     (`gnus-article-hide-boring-headers').  *Note Hiding Headers::.

`W W s'
     Hide signature (`gnus-article-hide-signature').

`W W p'
     Hide PGP signatures (`gnus-article-hide-pgp').

`W W P'
     Hide PEM (privacy enhavnced hessages) gruft
     (`gnus-article-hide-pem').

`W W c'
     Hide citation (`gnus-article-hide-citation').  Some variables for
     customizing the hiding:

    `gnus-cite-hide-percentage'
          If the cited text is of a bigger percentage than this
          variable (default 50), hide the cited text.

    `gnus-cite-hide-absolute'
          The cited text must be have at least this length (default 10)
          before it is hidden.

    `gnus-cited-text-button-line-format'
          Gnus adds buttons show where the cited text has been hidden,
          and to allow toggle hiding the text.  The format of the
          variable is specified by this format-like variable.  These
          specs are legal:

         `b'
               Start point of the hidden text.

         `e'
               End point of the hidden text.

         `l'
               Length of the hidden text.

    `gnus-cited-lines-visible'
          The number of lines at the beginning of the cited text to
          leave shown.

`W W C'
     Hide cited text in articles that aren't roots
     (`gnus-article-hide-citation-in-followups').  This isn't very
     useful as an interactive command, but might be a handy function to
     stick in `gnus-article-display-hook' (*note Customizing
     Articles::.).

   All these "hiding" commands are toggles, but if you give a negative
prefix to these commands, they will show what they have previously
hidden.  If you give a positive prefix, they will always hide.

   Also *note Article Highlighting::. for further variables for
citation customization.

   `gnus-signature-limit' provides a limit to what is considered a
signature.  If it is a number, no signature may not be longer (in
characters) than that number.  If it is a function, the function will be
called without any parameters, and if it returns `nil', there is no
signature in the buffer.  If it is a string, it will be used as a
regexp.  If it matches, the text in question is not a signature.


File: gnus.info,  Node: Article Washing,  Next: Article Buttons,  Prev: Article Hiding,  Up: Article Treatment

Article Washing
---------------

   We call this "article washing" for a really good reason.  Namely, the
`A' key was taken, so we had to use the `W' key instead.

   "Washing" is defined by us as "changing something from something to
something else", but normally results in something looking better.
Cleaner, perhaps.

`W l'
     Remove page breaks from the current article
     (`gnus-summary-stop-page-breaking').

`W r'
     Do a Caesar rotate (rot13) on the article buffer
     (`gnus-summary-caesar-message').

`W t'
     Toggle whether to display all headers in the article buffer
     (`gnus-summary-toggle-header').

`W v'
     Toggle whether to display all headers in the article buffer
     permanently (`gnus-summary-verbose-header').

`W m'
     Toggle whether to run the article through MIME before displaying
     (`gnus-summary-toggle-mime').

`W o'
     Treat overstrike (`gnus-article-treat-overstrike').

`W w'
     Do word wrap (`gnus-article-fill-cited-article').  If you use this
     function in `gnus-article-display-hook', it should be run fairly
     late and certainly after any highlighting.

`W c'
     Remove CR (`gnus-article-remove-cr').

`W L'
     Remove all blank lines at the end of the article
     (`gnus-article-remove-trailing-blank-lines').

`W q'
     Treat quoted-printable (`gnus-article-de-quoted-unreadable').

`W f'
     Look for and display any X-Face headers
     (`gnus-article-display-x-face').  The command executed by this
     function is given by the `gnus-article-x-face-command' variable.
     If this variable is a string, this string will be executed in a
     sub-shell.  If it is a function, this function will be called with
     the face as the argument.  If the `gnus-article-x-face-too-ugly'
     (which is a regexp) matches the `From' header, the face will not
     be shown.  The default action under Emacs is to fork off an `xv'
     to view the face; under XEmacs the default action is to display
     the face before the `From' header.  (It's nicer if XEmacs has been
     compiled with X-Face support--that will make display somewhat
     faster.  If there's no native X-Face support, Gnus will try to
     convert the `X-Face' header using external programs from the
     `pbmplus' package and friends.)  If you want to have this function
     in the display hook, it should probably come last.

`W b'
     Add clickable buttons to the article (`gnus-article-add-buttons').

`W B'
     Add clickable buttons to the article headers
     (`gnus-article-add-buttons-to-head').

