Returns a sequence of tuples representing all references to external files (such as textures, geometry files, and asset libraries) in the current scene.

The first item in each tuple is a hou.Parm object representing the parameter containing the file reference, and the second item is the path string. (The second item is a convenience; you can get the same string by calling Parm.unexpandedString().)

This can be useful when “preflighting”, to check that there are no references to files outside $HIP.

import os

hipdir = os.environ["HIP"]

for parm, path in hou.fileReferences():
    # Assume you have a function to check if one path is the descendant
    # of another path
    if not is_inside(hipdir, path):
        print("Problem: path %s is not inside the project dir %s" % (path, hipdir)

(The sequence does not include default images and geometry files from inside Houdini’s install location, for example default.bgeo in a File SOP.)