gexec/session.go
func (s *Session) ExitCode() int {
	s.lock.Lock()
	defer s.lock.Unlock()
	return s.exitCode
}
func (s *Session) ExitCode() int {
	s.lock.Lock()
	defer s.lock.Unlock()
	return s.exitCode
}
/*
ExitCode returns the wrapped command's exit code.  If the command hasn't exited yet, ExitCode returns -1.

To assert that the command has exited it is more convenient to use the Exit matcher:

	Eventually(s).Should(gexec.Exit())

When the process exits because it has received a particular signal, the exit code will be 128+signal-value
(See http://www.tldp.org/LDP/abs/html/exitcodes.html and http://man7.org/linux/man-pages/man7/signal.7.html)

*/