### Set OS/2 Run-Time Environment Variables

You can set most environment variables in the following ways:

- In your config.sys file, include set or variable-specific commands to assign values for environment variables. Optionally, if you put a semicolon at the end of such commands, you can later append values to the variables from the command line. Note, however, that this sets the variables for all processes, after the next time you reboot.
- Modify the variables from the command line or in a command file using the set command.
- From within your program, call the IBM C and C++ Compilers putenv function.

The functions that access the environment variables are not available when you use the subsystem libraries. To access the environment variables when you are using the subsystem libraries, you must use OS/2 APIs.

Application Run-Time Environment Variables