pdx Interactive Mode
pdx has an interactive mode. This mode
is very useful for testing function calls before you put them into
report templates or diagram definitions. And you can execute short
queries, for instance How many values are there in collection
x? or What was the all time
maximum? The interactive mode is started by the command line option
-i. pdx shows a prompt and
waits for input:
$ pdx -i
pdx 0.3.1 (2010-01-03 16:43:29 on castor, GNU/Linux 2.6.32-ARCH
x86_64)
>
At this prompt there are two instructions, ? and q, every other input will be
interpreted as function call.
The instruction ? lists
implementions of built-in functions. Without any parameters ? shows all known built-in functions
with their parameter types and their return type. ? accepts a regular expression which
can be used to shrink the result:
> ?min show all
implementions of the min-function
> ?a.* show all
functions beginning with a
> ?m.. show functions
beginning with m and
having two more characters
The instruction q
terminates the interactive mode and also pdx. This can also be achieved
by Ctrl-D or Ctrl-C.
The call of a function shows the result immediately. A call like
> (select "*")
shows all actual values of the default collection.