Get shape filename in attribute field using field calculator

Question

I apologize for crossposting against the ESRI geoprocessing forum, but it seems like this one gets answers. I'd like to have a modified append tool (ArcToolbox) that takes multiple shapefiles with point attribute data, and copies the inputted shapefile's name(s) to a "filename" attribute column, and then appends it to a target dataset. That way I can track where the data came from. The only way I can think to do this is something along the lines of the following:

for each shp in featureclasses:
  outFeatureClass = os.path.join("C:\GIS\Scripts\temp\temptrks", shp.strip(".shp"))
  arcpy.CopyFeatures_management(shp, outFeatureClass)
  arcpy.AddField_management(outFeatureClass, "filename", "TEXT", "","", "254")
  arcpy.CalculateField_management(outFeatureClass, "filename", str(shp), "PYTHON")

Then perform the append for each file in the new workspace.

What I'd like to do is be able to have a user drag and drop multiple shapefiles from multiple directories into a Multiple Value input box (like that in the Append tool).

I have two questions:

1. Is there an easier/better way to perform the task?
2. If not, what should I set the parameter type to (Multiple Value is not a selection).

Any advice is appreciated. Thank you all

Answer 1

In your ArcToolbox tool properties I'd set the parameter to a FeatureLayer/FeatureDataset with MultiValue=Yes and use some code like the following to get the filename:

for shp in featureclasses.split(';'):
    dsc = arcpy.Describe(shp)
    filename=dsc.CatalogPath #unicode is returned