shell多个脚本怎么并发执行

#!bin/bash   PRONUM=10               #进程个数   tmpfile="$$.fifo"        #临时生成管道文件 mkfifo $tmpfile exec 6<>$tmpfile rm $tmpfile   for(( i=0; i<$PRONUM; i++ )) do         echo "init." done >&6   for(( i = 0; i < ${count}; i++ )) do         read line         #echo $line         {                 commands                 echo "line${i} finished."         } >&6 & done <&6   wait

• sh a.sh  & 
  sh b.sh  & 
  sh c.sh &