public Map<String, String> getConfigPropsDefinedUsingFiles() {
    Map<String, String> configProps = new HashMap<>();
    for (ConfigSource fileSource : getFileSources()) {
      configProps.putAll(getConfigPropsFromSource(fileSource));
    }
    return configProps;
  }
Gets all the GemFire properties defined using file(s)

@return Map of GemFire properties and values set using property files
geode-core/src/main/java/org/apache/geode/internal/AbstractConfig.java