ctrl+Z 挂起

fg   将后台程序转入到前台  
  bg   将前台程序转入到后台  
   
  Does   a   good   farmer   neglect   a   crop   he   has   planted?  
  Does   a   good   teacher   overlook   even   the   most   humble   student?  
  Does   a   good   father   allow   a   single   child   to   starve?  
  Does   a   good   programmer   refuse   to   maintain   his   code?  
                              --   Geoffrey   James,   "The   Tao   of   Programming"  

 

or

 

 

先用jobs命令，得到任务号x，  
  然后用fg   %x,   bg   %x。