1 files changed, 12 insertions, 2 deletions
diff --git a/ext/socket/init.c b/ext/socket/init.c
index 83af8c5b0e..8e405609ba 100644
--- a/ext/socket/init.c
+++ b/ext/socket/init.c
@@ -786,7 +786,17 @@ rsock_getfamily(rb_io_t *fptr)
  * call-seq:
  *   error_code     -> integer
  *
- * Returns the raw error code occurred at name resolution.
+ * Returns the raw error code indicating the cause of the hostname resolution failure.
+ *
+ *    begin
+ *      Addrinfo.getaddrinfo("ruby-lang.org", nil)
+ *    rescue Socket::ResolutionError => e
+ *      if e.error_code == Socket::EAI_AGAIN
+ *        puts "Temporary failure in name resolution."
+ *      end
+ *    end
+ *
+ * Note that error codes depend on the operating system.
  */
 static VALUE
 sock_resolv_error_code(VALUE self)
@@ -802,7 +812,7 @@ rsock_init_socket_init(void)
      */
     rb_eSocket = rb_define_class("SocketError", rb_eStandardError);
     /*
-     * ResolutionError is the error class for socket name resolution.
+     * Socket::ResolutionError is the error class for hostname resolution.
      */
     rb_eResolution = rb_define_class_under(rb_cSocket, "ResolutionError", rb_eSocket);
     rb_define_method(rb_eResolution, "error_code", sock_resolv_error_code, 0);