SpecTcl Programming Guide.
Prev	Chapter 12. Dynamic processing pipelines

12.2. Using the pman command to create and select pipelines

In this section, we are going to assume that SpecTcl has the code described in the previous section and therefore there are four event processors registered: evp1, evp2, evp3 and filter. We'll create two pipelines. One called raw which will contain the user written evp* event prociessors and one called filter which contains the filter event processor. We'll then select the raw event processing pipeline to be the one SpecTcl uses.

Once more, all this could be done programatically using the pipeline manager object, but this method is more flexible and allows pipeline management to be added to your experiment specific Tcl/Tk GUI without any additional C++ coding.

Example 12-2. Using the pman SpecTcl command

pman mk raw                                
foreach proc [list evp1 evp2 evp3] {
    pman add raw $proc                     
}

pman mk filter                             
pman add filter filter

pman use raw

: The pman command is a command ensemble. This means that it requires a subcommand to tell it what to do. The mk subcommand creates new pipelines. This line creates a new event processing pipeline called raw
: This loop adds the user written event processors we registered in the C++ code in the previous section to the raw pipeline. The list in the foreach loop determines the order in which the event processors are called.
: Similarly, this pair of commands creates the pipeline named filter and makes the filter event processor its only element. Pipeline names must be unique, and event processor names must be unique, but the namespaces for pipelines and event processors are distinct allowing the pipeline to have the same name as an event processor.
: SpecTcl only runs a singl event processing pipeline at a time. When it starts executing, a pipeline named default is used. The use subcommand specifies a new pipeline to be used by SpecTcl to analyze data.; We could have equally well just added our raw event processors to the default pipeline not bothering with a raw pipeline. We chose not to for illustrative purposes, and to give that pipeline a better name.; The same SpecTcl executable can read filter files by simply doing a pman use filter at a later time.