log_redirect_stderr_to
void log_redirect_stderr_to(const char *);
log_redirect_stderr_to(NULL);
log_redirect_stderr_to(logfile);
log_redirect_stderr_to(cp);
log_redirect_stderr_to(cp);
log_redirect_stderr_to(NULL); /* dup can clobber log fd */
log_redirect_stderr_to(cp);
log_redirect_stderr_to(NULL);