Setting Environment Variables in SYSTEM Commands

About this task

When the operating-system command that SYSTEM specifies is executed, no guarantee exists that any environment variables that the user application sets are passed to the operating system. If you set an environment variable in a SYSTEM command, the setting is only valid during that SYSTEM command.

To avoid this potential problem, the following method is recommended to ensure that any environment variables that the user application requires are carried forward to the operating system.


To Change Environment Settings for an Operating System Command
  1. Create a shell script (on UNIX™ systems) or a batch file (on Windows™ platforms) that sets up the desired environment and then executes the operating system command.
  2. Use the SYSTEM command to execute the shell script or batch file.


This solution has an additional advantage: if you subsequently need to change the environment, you can modify the shell script or the batch file without needing to recompile the SPL routine.

For information about operating system commands that set environment variables, see the HCL OneDB™ Guide to SQL: Reference.