private Set<String> fetchFunctions() {
    Set<String> funcs = null;
    if (desc.getPattern() != null) {
      funcs = FunctionRegistry.getFunctionNamesByLikePattern(desc.getPattern());
      LOG.info("Found {} function(s) using pattern {} matching the SHOW FUNCTIONS statement.", funcs.size(),
          desc.getPattern());
    } else {
      funcs = FunctionRegistry.getFunctionNames();
    }

    return funcs;
  }
Operation process of showing the functions.
ql/src/java/org/apache/hadoop/hive/ql/ddl/function/show/ShowFunctionsOperation.java