8445cf17_aging_Centre_Pipelining_System__Description
[Command] --prqst [Description] 
The prerequisites that must be satisfied before this stage can be run. It is the --prqst option which gives rppl its power, and allows it to take advantage of the coarse parallelism provided by the batch queueing system. The syntax for --prqst is a little different, however. Here's an example line: --prqst ${dsid}: step_mincresample_t1 SUCCEED and step_mincresample_t1 SUCCEED. The first part of the expression, ${dsid}, provides the context for rppl to interpret the subsequent step definitions. This means that the following steps have to have succeed for this dataset ID. In almost all cases this will be the dsid of the current file being processed. After that come the names of the steps (taken from their --stageName variable) preceded by "step_", and the condition that is to be met (currently only SUCCEED is supported). More than criteria can be required with the "and" keyword. Also note that this is the only part of the pipeline definition which does not require a semi-colon at the end.
RPPL: Brain Imaging Centre Pipelining System
Description