bash中使兩條指令同時運行

在bash shell使兩個任務同時運行

(hadoop jar /home/xcp/hadoop-1.0.0/hadoop-examples-1.0.0.jar sort input output)&
pid1=$! #獲取進程號
(sleep 15; hadoop job -list | grep job_ | awk '{print $1} | grep job_' > tmp)&
pid2=$! #獲取進程號
wait ${pid1} ${pid2} #等待進程完成
jobId=`cat tmp` 
cost=$[$end_time-$start_time]