Re: [Groff] Formatting algorithm, an experiment

[Steffen Nurpmeso]

Hello Ralph,

Ralph Corderoy <address@hidden> wrote:
 |Hi Steffen,
 |
 |>> The closest is
 |>> http://www.iana.org/assignments/media-types/application/gzip which
 |>> leaves the tar for the user to fathom out if left to MIME types
 |>> alone.
 |>
 |> [http://svn.apache.org/viewvc/tika/trunk/tika-core/src/ma\
 |> in/resources/org/apache/tika/mime/tika-mimetypes.xml]
 |> lists the extension tgz regulary thereunder
 |> 
 |>   <mime-type type="application/gzip">
 |>     <_comment>Gzip Compressed Archive</_comment>
 |>     <alias type="application/x-gzip"/>
 |>     <alias type="application/x-gunzip"/>
 |>     <alias type="application/gzip-compressed"/>
 |>     <alias type="application/gzipped"/>
 |>     <alias type="application/gzip-compressed"/>
 |>     <alias type="application/x-gzip-compressed"/>
 |>     <alias type="gzip/document"/>
 |>     <magic priority="45">
 |>       <match value="\037\213" type="string" offset="0" />
 |>       <match value="\x1f\x8b" type="string" offset="0" />
 |>     </magic>
 |>     <glob pattern="*.tgz" />
 |>     <glob pattern="*.gz" />
 |>     <glob pattern="*-gz" />
 |>     <glob pattern="*.emz" />
 |>   </mime-type>
 |
 |Interesting, but the comment seems wrong, since foo.gz need not be an
 |archive, i.e. a collection of other things, and it's lumping foo.gz and
 |foo.tgz together, so no indication that one of them is a tar file.

it's a community project, some fuzziness seems to be allowed..
Eventually i know of no other source that is so comprehensive.
(And i personally only use the glob entries.)

 |MIME types just don't seem to allow layering.  That file also has a

We guess the reason for this is to ease processing with handler
chains, i.e., subtype-of-text -> use text handler.  Or something
similar.

 |couple of tar types.
 |
 |    <mime-type type="application/x-tar">
 |        <magic priority="40">
 |            <!-- POSIX tar archive -->
 |            <match value="ustar\0" type="string" offset="257" />
 |        </magic>
 |        <glob pattern="*.tar"/>
 |    </mime-type>
 |
 |    <mime-type type="application/x-gtar">
 |        <_comment>GNU tar Compressed File Archive (GNU Tape 
Archive)</_comment>
 |        <magic priority="50">
 |            <!-- GNU tar archive -->
 |            <match value="ustar  \0" type="string" offset="257" />
 |        </magic>
 |        <glob pattern="*.gtar"/>
 |        <sub-class-of type="application/x-tar"/>
 |    </mime-type>
 |
 |The second's comment suggests it's compressed but then it wants `ustar'
 |at offset 257 which is uncompressed.

Apart of the comment it (the magic) seems right, however.

 |It's a mess.  HTTP can ship an application/x-tar with a Content-Encoding
 |of gzip, but that's not the same thing as the client should ungzip to
 |deliver the tar;  not what's wanted.
 |
 |This seems to be getting off-groff topic.  :-)

Oh, after fiddling with unsupported linker options etc. to compile
the showcase i got a SIGBUS.  You know, as in "Bus stop, wet day,
she's there" etc.  Only the umbrella is still missing.
Ciao,

--steffen