list g_env;         // set to env in main()
int g_envvar;       // set to 1 if the env var is defined

string getenvSF(string var)
{
    int idx;

    for (idx = sizeof(g_env); idx; )
    {
        idx -= 2;
        if (element(idx, g_env) == var)
        {
            g_envvar = 1;
            return element(idx + 1, g_env);
        }
    }
    g_envvar = 0;
    return "";
}
