Reading from the filesystem with Postgres

Let’s try to make the following SQL statement work:

SELECT file.read('/tmp/test.txt');  

.. Now we just need to fill in the function with logic to read from the filesystem!

CREATE FUNCTION file.read(file text)  
  RETURNS text AS $$
    DECLARE
      content text;
      tmp text;
    BEGIN
      file := quote_literal(file);
      tmp := quote_ident(uuid_generate_v4()::text);

      EXECUTE 'CREATE TEMP TABLE ' || tmp || ' (content text)';
      EXECUTE 'COPY ' || tmp || ' FROM ' || file;
      EXECUTE 'SELECT content FROM ' || tmp INTO content;
      EXECUTE 'DROP TABLE ' || tmp;

      RETURN content;
    END;
  $$ LANGUAGE plpgsql VOLATILE;