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-[[!meta copyright="Copyright © 2009 Free Software Foundation, Inc."]]
-
-[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
-id="license" text="Permission is granted to copy, distribute and/or modify this
-document under the terms of the GNU Free Documentation License, Version 1.2 or
-any later version published by the Free Software Foundation; with no Invariant
-Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license
-is included in the section entitled
-[[GNU Free Documentation License|/fdl]]."]]"""]]
-
-# nsmux
-
-`nsmux` implements the simplest use-case of namespace-based translator
-selection (see below).
-
-To use `nsmux` do the following:
-
- $ settrans -a <node> nsmux <directory>
-
-After this operation `<node>` will be a mirror of `<directory>` with
-namespace-based translator selection functionality enabled.
-
-Please note that due to some details `nsmux` may complain a lot when
-run as a normal user. This matter is the most urgent on the TODO
-list.
-
-## Source
-
-`nsmux` translator can be obtained with the following command:
-
- $ git clone git://github.com/scolobb/nsmux.git
-
-`filter` translator can be obtained with the following command:
-
- $ git clone git://github.com/scolobb/filter.git
-
-The filter is not yet working.
-
-It is highly probable that soon the code will be moved to Savannah.
-
-## Namespace-based Translator Selection
-
-Namespace-based translator selection is the special technique of using
-"magic" filenames for both accessing the file and setting translators
-on it.
-
-A "magic" filename is a filename which contains an unescaped sequence
-of two commas: ",,". This sequence can be escaped by adding another
-comma: ",,,". In the magic filename the part up to the first double
-commas is interpreted as the filename itself; the remaining segments
-into which the string is split by occurrences of ",," are treated as
-names of translators located under `/hurd/`.
-
-The simplest advantage before traditional way of setting
-translators is shown in the following examples. Compare this
-
- $ settrans -a file translator1
- $ settrans -a file translator2
- $ cat file
-
-to this:
-
- $ cat file,,translator1,,translator2
-
-One simple command versus three more lengthy ones is an obvious
-improvement. However, this advantage is not the only one and,
-probably, not even the most important.
-
-What is a good candidate for the most important advantage is that
-translators requested via "magic" filenames are session-bound. In
-other words, by running `cat file,,translator` we set a translator
-visible *only* to `cat`, while the original file remains untranslated.
-Such session-specific translators are called **dynamic** and there is
-no (theoretical) way for a client to get a port to a dynamic
-translator requested by another client.
-
-Obviously, dynamic translators can be stacked, similarly to static
-translators. Also, dynamic translator stacks may reside on top of
-static translator stacks.
-
-An important operation of namespace-based translator selection is
-*filtering*. Filtering basically consists in looking up a translator
-by name in the stack and ignoring translators located on top of it.
-Note that filtering does not mean dropping some translators: in the
-current implementation a filter is expected to be a normal dynamic
-translator, included in the dynamic translator stack similarly to
-other translators.
-
-An important detail is that filtering is not limited to dynamic
-translator stacks: a filter should be able to descend into static
-translator stacks as well.
-
-Although the concept of filtering may seem purely abstract in the
-simplest use-case of setting dynamic translators on top of files, the
-situation changes greatly when dynamic translator stacks on top of
-directories are considered. In this case, the implementation of
-namespace-based translator selection is expected to be able to
-propagate the dynamic translators associated with the directory down
-the directory structure. That is, all files located under a directory
-opened with magic syntax, are expected to be translated by the same
-set of translators. In this case having the possibility to
-specifically discard some of the translators set up on top of certain
-files is very useful.
-
-Note that the implementation of propagation of dynamic translators
-down directories is not fully conceived at the moment. The
-fundamental problem is distinguishing between situations when the
-dynamic translators are to be set on the underlying files of the
-directory or on the directory itself.
-
-## Currently Implemented
-
-Currently there a working (though not heavily tested) implementation
-of the simplest use-case of namespace-based translator selection in
-the form of translator `nsmux`. The filter is partially implemented
-and this is the immediate goal. Propagating translators down
-directories is the next objective.