In general a variable argument specification consists of one or more fields separated by :
with the number of fields determining their interpretation.
Empty fields are treated as their defaults or matching anything, depending on the context.
All fields are considered as regular expressions to be matched against the whole field. In general this means that the simple case of specifying a whole field literally will simply work. It also allows for more complex specifications using special characters. The regular expression syntax is similar to Perl’s form with some of the more advanced forms (e.g. negative lookahead) not supported. When using regular expressions, be sure that they are properly escaped if passed from a command line shell.
- One field
-
When only a single field is present it is interpreted as a variable name. The station, archive, and flavors matching are left at their default values. For example
BsG_S11
selects only green scattering from the S11 instrument. - Two fields
-
When the specification consists of two fields, they specify the archive and variable in order. For example
raw:BsG_S11
selects the green scattering from theraw
archive. - Three or more fields
-
With three fields the first three are the station, archive, and variable, in order. For example
bnd:raw:BsG_S11
selects the green scattering from theraw
archive for theBND
station.Any remaining fields after the first three form the flavors selection. Each field in a flavors selection specifies a single flavor to match. The interpretation depends on the first character of the field:
- No special character or a
+
-
The field is added to the list of flavors required to be present. For example
pm1
and+pm1
both require thePM1
flavor. - Starting with a
!
or-
-
The field is added to the list of flavors required to be absent. For example
!pm10
and-pm10
both exclude data with thePM10
flavor. - Starting with a
=
-
The field is added to the exact flavors specification. Any required or excluded flavors are ignored. The exact flavors specification gives the full list of flavors matched exactly. For example
=pm25
selects only data with just thePM25
flavor and ignores all other data.
- No special character or a
BsG_S11
Bs[BGR]_S11
::BsG_S11:pm10
:.*_meta::-pm1:-pm10:-pm25
(brw|smo)::BsG_S11:=
The meaning of the individual components is described here.