To help you manage your NWN data more efficiently, nwn-lib supports user-written, small (or large) scripts that follow the unix principle of piping.
Filter Scripts act as an argument to nwn-gff, and will be invoked as a pass-through for data filtering and transformation. Filters always depend on self being a Gff element.
An example of a filter script would be a snippet, that truncates all floating points to a fixed size before outputting them to yaml.
Filter scripts are usually not executable by themself.
Standalone scripts are shell scripts invokable from command line, and do not operate on specific files; instead, they get invoked with their own (optional) parameters and act independently of data sources.
An example for a standalone script would be a script, that asks the user for a name and then generates a random item from that.
You can create standalone scripts by prefixing them with the proper shebang:
#!/usr/bin/env nwn-dsl
If you are on systems which do not support executable scripts this way, simply call them with nwn-dsl.
DSL stands for domain-specific-language by the way, and this is quite a stretch, considering your scripts will be written in plain old ruby.
The currently-running script name is in $SCRIPT - you can override this to print a custom name in, for example, log.
There are various helpers available to scripts. See NWN::Gff::Scripting for a list of helper methods; additionally you can use all other API functions, of course.
There are some examples packaged together with nwn-lib, check the scripts/ directory with the distribution.