问launchctl列表的状态列中的数字意味着什么？

EN

 list [-x] [label]
          With no arguments, list all of the jobs loaded
          into launchd in three columns. The first column
          displays the PID of the job if it is running.
          The second column displays the last exit status
          of the job. If the number in this column is
          negative, it represents the negative of the
          signal which killed the job.  Thus, "-15" would
          indicate that the job was terminated with
          SIGTERM. The third column is the job's label.