gnus: Non-ASCII Group Names
2.17 Accessing groups of non-English names
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There are some news servers that provide groups of which the names are
expressed with their native languages in the world. For instance, in a
certain news server there are some newsgroups of which the names are
spelled in Chinese, where people are talking in Chinese. You can, of
course, subscribe to such news groups using Gnus. Currently Gnus
supports non-ASCII group names not only with the ‘nntp’ back end but
also with the ‘nnml’ back end and the ‘nnrss’ back end.
Every such group name is encoded by a certain charset in the server
side (in an NNTP server its administrator determines the charset, but
for groups in the other back ends it is determined by you). Gnus has to
display the decoded ones for you in the group buffer and the article
buffer, and needs to use the encoded ones when communicating with
servers. However, Gnus doesn’t know what charset is used for each
non-ASCII group name. The following two variables are just the ones for
telling Gnus what charset should be used for each group:
‘gnus-group-name-charset-method-alist’
An alist of select methods and charsets. The default value is
‘nil’. The names of groups in the server specified by that select
method are all supposed to use the corresponding charset. For
example:
(setq gnus-group-name-charset-method-alist
'(((nntp "news.com.cn") . cn-gb-2312)))
Charsets specified for groups with this variable are preferred to
the ones specified for the same groups with the
‘gnus-group-name-charset-group-alist’ variable (see below).
A select method can be very long, like:
(nntp "gmane"
(nntp-address "news.gmane.org")
(nntp-end-of-line "\n")
(nntp-open-connection-function
nntp-open-via-rlogin-and-telnet)
(nntp-via-rlogin-command "ssh")
(nntp-via-rlogin-command-switches
("-C" "-t" "-e" "none"))
(nntp-via-address ...))
In that case, you can truncate it into ‘(nntp "gmane")’ in this
variable. That is, it is enough to contain only the back end name
and the server name.
‘gnus-group-name-charset-group-alist’
An alist of regexp of group name and the charset for group names.
‘((".*" . utf-8))’ is the default value if UTF-8 is supported,
otherwise the default is ‘nil’. For example:
(setq gnus-group-name-charset-group-alist
'(("\\.com\\.cn:" . cn-gb-2312)
(".*" . utf-8)))
Note that this variable is ignored if the match is made with
‘gnus-group-name-charset-method-alist’.
Those two variables are used also to determine the charset for
encoding and decoding non-ASCII group names that are in the back ends
other than ‘nntp’. It means that it is you who determine it. If you do
nothing, the charset used for group names in those back ends will all be
‘utf-8’ because of the last element of
‘gnus-group-name-charset-group-alist’.
There is one more important variable for non-ASCII group names:
‘nnmail-pathname-coding-system’
The value of this variable should be a coding system or ‘nil’. The
default is ‘nil’ in Emacs, or is the aliasee of the coding system
named ‘file-name’ (a certain coding system of which an alias is
‘file-name’) in XEmacs.
The ‘nnml’ back end, the ‘nnrss’ back end, the agent, and the cache
use non-ASCII group names in those files and directories. This
variable overrides the value of ‘file-name-coding-system’ which
specifies the coding system used when encoding and decoding those
file names and directory names.
In XEmacs (with the ‘mule’ feature), ‘file-name-coding-system’ is
the only means to specify the coding system used to encode and
decode file names. On the other hand, Emacs uses the value of
‘default-file-name-coding-system’ if ‘file-name-coding-system’ is
‘nil’ or it is bound to the value of
‘nnmail-pathname-coding-system’ which is ‘nil’.
Normally the value of ‘default-file-name-coding-system’ in Emacs or
‘nnmail-pathname-coding-system’ in XEmacs is initialized according
to the locale, so you will need to do nothing if the value is
suitable to encode and decode non-ASCII group names.
The value of this variable (or ‘default-file-name-coding-system’)
does not necessarily need to be the same value that is determined
by ‘gnus-group-name-charset-method-alist’ and
‘gnus-group-name-charset-group-alist’.
If ‘default-file-name-coding-system’ or this variable is
initialized by default to ‘iso-latin-1’ for example, although you
want to subscribe to the groups spelled in Chinese, that is the
most typical case where you have to customize
‘nnmail-pathname-coding-system’. The ‘utf-8’ coding system is a
good candidate for it. Otherwise, you may change the locale in
your system so that ‘default-file-name-coding-system’ or this
variable may be initialized to an appropriate value.
Note that when you copy or move articles from a non-ASCII group to
another group, the charset used to encode and decode group names should
be the same in both groups. Otherwise the Newsgroups header will be
displayed incorrectly in the article buffer.
Info Catalog
gnus: Group Topics
gnus: Group Buffer
gnus: Misc Group Stuff