setenv <var-name> <value>
setenv -<var-name>

In the first usage, SETENV sets the environment variable <var-name> to <value>. This new value will be visible to all of the processes that you EXEC. In the second usage, the environment variable <var-name> is unset (deleted), and is no longer visible to EXEC processes.

Some systems (like Solaris) make changing and deleting environment variables painful. Upon these kinds of systems, EPIC may output a warning advising you that setting an environment variable will result in a memory leak which is unavoidable. These systems also do not have an easy way to unset environment variables. If you try, you will get a warning telling you this.