We have installed some code which is running in both the ABAP and JAVA environment, and some functionality of this code is determined by the setting of operating system environment variables. We have therefore changed the .sapenv_<host>.csh and .sapenv_<host>.sh scripts found in the <sid>adm user home directory. This works, but we are wondering what happens when SAP is upgraded, and if these custom shell script changes to the .sh and .csh scripts will be overwritten during such an upgrade. Is there a better way to set environment variables so they can be used by the SAP server software when it has been started from <sid>adm user ?