Author Topic: uu.trid.xml for Base64 variant of UUencoded text *.UU  (Read 1074 times)

jenderek

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uu.trid.xml for Base64 variant of UUencoded text *.UU
« on: February 13, 2022, 01:08:17 AM »
Hello trid users,

some days ago i recompiled lilo boot loader source. In images sub directory
are files with UU name extension.

When i run TrID on such examples these are described as "Unknown!" (see
appended output/trid-old.txt). According to Makefile in that directory these
examples are uuencoded text, which are normally described by uue.trid.xml as
"UUencoded/XXencoded text" and possible file name extension UUE, UU or XXE.

So i run tridscan to generate definition uu.trid.xml for these variants
examples. The reference URL is in principal the same. That is expressed by
line like:
   <RefURL>http://fileformats.archiveteam.org/wiki/Uuencoding</RefURL>

The mime type for such text files is still the same, that is mentioned on
FreeDesktop.org shared MIME database specification. That information can be
found for example on reposcope.com web site. So mime type is shown by line
like:
   <Mime>text/x-uuencode</Mime>

For my inspected examples i only found one file name extension. That is
expressed by line like:
   <Ext>UU</Ext>

In principal the file format is similar, but base64 encoding is used
here. So this is visible by starting keyword "begin-base64" instead of
"begin". This is expressed inside front block by xml construct like:
   <Bytes>626567696E2D62617365363420</Bytes>
   <ASCII> b e g i n - b a s e 6 4</ASCII>
   <Pos>0</Pos>

The first line consist of three space separated items. Second item is the
octal permission mode like 644. Third item it name, which is most cases the
original file name like debianlilo.bmp. Because of separating these items by
one space character after the permission mode i get always a space character
at offset 16. That is expressed by line like:
   <Bytes>20</Bytes>
   <Pos>16</Pos>

With the new TrID definition all of my inspected UU examples are now
described correctly as "UUencoded Base64 text" (see appended output/trid-v-new.txt).

TrID definitions, some examples and output are stored in archive
uu_.zip.

With best wishes
Jörg Jenderek