Defnyddio newidynnau amgylchedd i osod gosodiadau' r dirprwy. Fel rheol, defnyddir newidynnau amgylchedd megis HTTP_ PROXY a NO_ PROXY mewn arsefydliadau UNIX aml- ddefnyddiwr, lle bo angen i gymwysiadau graffeg a di- raffeg rannu' r un gwybodaeth ffurfweddu dirprwy.
Use environment variables to configure the proxy settings. Environment variables such as HTTP_PROXY and NO_PROXY are usually used in multi-user UNIX installations, where both graphical and non-graphical applications need to share the same proxy configuration information.