Programming Guide - Actian

Appendix B: Operating System DifferencesThis section contains the following topics:How You Can Use File Specifications (see page 489)Operating System Commands (see page 489)Operating system differences affect your OpenROAD programs when you:• Specify file names• Call operating system commandsWhen you are coding for more than one operating system, you can use theOperatingSystem attribute of SessionObject to check the current operatingsystem for the running application. For more information about this attribute,see the Language Reference Guide online help.How You Can Use File SpecificationsFile specifications, which are rarely used in 4GL, are required for the following:• FileHandle attribute of BitmapObject and StringObject• SQL copy statement• call runimage statementOne way to use file specifications is to store them in an Ingres variable. Atruntime, use the GetEnv method of the SessionObject system class todetermine the file specification. For example:filename = CurSession.GetEnv('MYAPP_FILENAME');Another way to use file specifications is to store your file specifications in adatabase table.Operating System CommandsThe OpenROAD call system statement lets you execute a single operatingsystem command from your 4GL code. When you use this statement in aportable application, you must account for the differences between commandson the various operating systems.Operating System Differences 489