[IDD #JHR-989766]: Assistance in becoming a Unidata user

Hi Tim,

re:
> I'm just starting to see how some of the config files are made up.  It looks 
> like
> it's just Perl, specifically Perl regular expressions.

The LDM uses extended regular expressions.  I am not 100% sure that this is 
exactly
the same as Perl, but it should be very close.

re:
> Am I correct with my assumption below?
> 
> ___________________________
> 
> Notifyme feed
> 
>-----------------------------------------------------------------------------------------------------------------------------------------------
> 
> Nov 08 19:24:27 notifyme[14980] INFO:     4652 20111108191322.461 NEXRAD3 
> 220186873  SDUS72 KMHX 081912 /pN0ZMHX
> Nov 08 19:24:27 notifyme[14980] INFO:      158 20111108191322.461 NEXRAD3 
> 220186874  SDUS34 KHGX 081908 /pNMDHGX
> Nov 08 19:24:27 notifyme[14980] INFO:     2033 20111108191322.461 NEXRAD3 
> 220186875  SDUS36 KSGX 081903 /pNVWSOX
> Nov 08 19:24:27 notifyme[14980] INFO:     2083 20111108191322.604 IDS|DDPLUS 
> 220186890  SAUS60 KWOH 081912 /pRRSTFX
> Nov 08 19:24:27 notifyme[14980] INFO:      342 20111108191322.461 NEXRAD3 
> 220186876  SDUS76 KSGX 081903 /pNETSOX
> 
> Pqact.conf entry
> 
> -----------------------------------------------------------------------------------------------------------------------------------------------
> 
> IDS|DDPLUS     ^SAUS(..) (....)
> FILE    surface/US/\2/\1
> 
> Would I be correct to assume that this config entry grabs the “IDS|DDPLUS”
> line with properties that start with “SAUS” followed by 2 characters, a space,
> then 4 more characters?

Yes, this pattern-action entry matches the LDM/IDD Product ID that begins with 
"SAUS";
is followed by any two characters; is followed by one space; and finally is 
followed by
any 4 characters in the IDS|DDPLUS datastream.

NB:  The regular expression will match Product IDs that have characters past the
4 that are matched at the end of this extended regular expression.  They are 
not,
however, available for use in the action (FILE  surface/US/\2/\1) because they
were not "trapped" by a parenthetical expression.

re:
> Effectively getting everything highlighted above, grabbing only the “60” and
> “KWOH” and outputting a file name of “surface/US/KWOH/60” .

Yes.  Furthermore, since the LDM change roots actions to ~ldm/data, the
full output file name will be ~ldm/data/surface/US/KWOH/60.

re:
> I’m not sure if these regex’s are grabbing from the stream as they are 
> represented
> by ‘notifyme’ or if it’s parsing something else.

The extended regular expressions in a pattern-action file are used to match 
against
the full Product ID, and 'notifyme' lists show the full Product ID.  'notifyme' 
output
includes additional information that can be of interest.

In the line:
Nov 08 19:24:27 notifyme[14980] INFO: 4652 20111108191322.461 NEXRAD3 220186873 
SDUS72 KMHX 081912 /pN0ZMHX

we find:

Nov 08 19:24:27             - date/time that 'notifyme' recorded the product
INFO:                       - indication of information type of message
4652                        - product size [bytes]
20111108191322.461          - CCYYMMDDHHmmss.msec the product was "created" 
(first put into an
                              LDM queue
NEXRAD3                     - feed type that the product was in
220186873                   - feed-specific info (typically a sequence number 
or something similar)
SDUS72 KMHX 081912 /pN0ZMHX - full Product ID 

The Product ID is the _only_ thing available to match against in pattern-action 
entries.

Cheers,

Tom
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Ticket Details
===================
Ticket ID: JHR-989766
Department: Support IDD
Priority: Normal
Status: Closed