Used to set environment variables for the current process.
expression should evaluate to a string of the form:
where EnvVarName is the name of a valid environment variable and value is any string that makes sense to variable being set.
If PUTENV function succeeds it returns a Boolean TRUE value, if it fails it will return a Boolean FALSE value.
PUTENV only sets environment variables for the current process and processes spawned (say by EXECUTE) by this process. These variables are known as export only variables.
See also GETENV.