[GEMPAK #GXW-674499]: LDM support

Hi Kevin,

Sorry for the slow reply...

re:
> After installing gempak I receive this error:
> 
> 20160916T221545.472452Z pqact[24202] ERROR filel.c:1542:pipe_open() No
> such file or directory
> 20160916T221545.472504Z pqact[24202] ERROR filel.c:1542:pipe_open()
> Couldn't execute decoder
> "decoders/dcgrib2";PATH=/usr/local/ldm/ldm-6.13.4/bin:/usr/local/ldm/decoders:/usr/local/ldm/util:/usr/local/ldm/bin:/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin:/usr/local/ldm/.local/bin:/usr/local/ldm/bin
> 
> 
> I made a directory /usr/local/ldm/bin/decoders where it should find the
> decoder which is not being executed, but I keep getting the same error.

The reason for the problem you are now facing has its roots in the
setup of the LDM in the pre-v6.12.x days and what they are now.  In
the past, it was assumed that the current working directory for LDM
processes would be the HOME directory of the user 'ldm'.  With the
introduction of more recent LDMs, the current working directory for
processes like 'pqact' (the thing that executes the actions in 
pattern-action files) is defined in the LDM registry, ~ldm/etc/registry.xml.
I think that the easiest way forward for you at this point is to
modify the LDM registry so that the current working directory for
'pqact' is ~ldm.  Here is what to do:

<as 'ldm'>
-- stop the LDM

ldmadmin stop

- edit the LDM registry file and in the <pqact> </pqact> section

  change:

<datadir-path>/usr/local/ldm/var/data</datadir-path>

  to:

<datadir-path>/usr/local/ldm</datadir-path>

- while at it, also change the <datadir-path> setting in the <pqsurf></pqsurf>
  section in exactly the same way as in the <pqact></pqact> section:

The end result of this change will be the current working directory
for 'pqact' and 'pqsurf' (not used by many users) will be such that
the relative reference to GEMPAK decoders (e.g., decoders/dcmetr, etc.)
will work (assuming that you copied all of the GEMPAK decoders to
the /usr/local/ldm/decoders directory.

One other thing to do while you are at it is:

- make sure that the ~ldm/decoders (and ~ldm/util) directories are in
  the PATH of the LDM user

  By the way, it is _much_ better to put the ~ldm/bin, ~ldm/decoders
  and ~ldm/util directories at the end of the PATH.  Putting it at
  the front of PATH could cause problems if, for instance, you
  inadvertently copied the GEMPAK 'ps' command to the ~ldm/decoders
  directory.

  If you need to make changes to the 'ldm's PATH, please make sure
  that the changes are active before restarting the LDM.

Please let us know your results after implementing the changes above.

Cheers,

Tom
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Ticket Details
===================
Ticket ID: GXW-674499
Department: Support GEMPAK
Priority: Normal
Status: Closed
===================
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