The Message ID section maps message TYPE, SUB-TYPE and filenames to an ID.
All three fields are perl regular expressions. The TYPE is a generic data type. The
SUB-TYPE is a more specific classification within that particular type. The filename
is the name of the file being processed. There are 6 optional fields after the Message ID.
The optional fields are used by the FPTGET command. The six fields are:
- local directory
- local filename
- local file permissions
- file owner
- file group
- purge parameter
The
local filename and local directory may contain back references into the filename. A back
reference is simply the tagged expression in the third column regular expression. The
following example shows a Message ID line:
This line will match:
- TYPE=GRIB
- SUB-TYPE=eta29
- filename=/com/eta/prod/eta.960618/meso.tm00.003Z
The parenthesis in the third field are the perl tagged expressions. The $1 and $2 in the
sixth (local file name) field will use these tagged expressions to create the local file name.
The data, if transferred from the remote machine will be stored in a directory called
/pub/grib/eta29 and the filename will be eta29_960618_meso.tm00.003Z. DBNet will then set the
file permissions to 644 and try to change the owner to 1005 and group to 100.
Some implementations of Unix will not allow users to change file ownership.