Hello trid users,
some days ago i migrate a Windows 7 system to 10 and a HP printer does
not work afterwards. To locate the errors i redirect printer output to
file. In the end the printer output was identified as HP Printer
Command Language by trid. For interest i run trid on other printer
output and PCL test examples found on Ghostscript PCL interpreter site
at
https://www.ghostscript.com/GhostPCL.html.
There i found examples with pxl or px3 extension like in examples
frs96.pxl and tiger.px3. When running trid on such samples these are
recognized as "HP Printer Command Language (UEL)" by
hp-pcl-uel.trid.xml (See appended output/trid-old.txt).
In that trid definition file only 2 file name extensions (PCL and PRN)
are mentioned. So i update hp-pcl-uel.trid.xml with these 2 additional
extensions which is expressed by changed line:
<Ext>PCL/PRN/PXL/PX3</Ext>
Unfortunately these 2 new extensions only occur in context of
Ghostscript or PCL converter. I found no location with explanation for
these extensions and file format. So i do myself looking for facts.
For comparison reason i run other utilities. The file(1) command does
describe examples as "HP Printer Job Language data" (see appended
output/file-5.28.txt).
There i saw for example null.pxl first hint what is specific for the 2
new extensions. This is a printer job command starting with phrase
"ENTER LANGUAGE = " with some optional white space separations.
According to HP PCL XL 2.0 Technical Reference Rev 2.2 for early HP
printers this is followed by phrase like PCL or POSTSCRIPT to switch
printer language. After version level 5 HP introduced PCL6. One part is
compatible with older levels. Another part is new. That is called PCL
6 "Enhanced" or formerly known as PCL XL or PXL.
To switch printer language the printer file now contains a command
phrase like "@PJL ENTER LANGUAGE = PCLXL".
Because white space before and after equal sign is optional this gives
in new trid definition in global string section 2 new lines like:
<String>PJL ENTER LANGUAGE</String>
<String>PCLXL</String>
So the new variant describes the PCL6 with new features. So i name
trid definition file as hp-pcl6-uel.trid.xml.
Apparently to distinguish the new file format from older printer output
instead file name extension PCL now PX3 or PXL as abbreviation for
PCL XL is chosen.
With the updated and new variant trid definition all my PCL6 samples are now
described more precisely ( see appended output PCL.zip). I hope that
my XML files can be used in future version of triddefs.
With best wishes
Jörg Jenderek
