shell多线程写法

网上很多类似的文章, 这里做下笔记而已

#!/bin/sh
function a_sub {
    return
}

starttime=$(date +%s)
export starttime
tmp_fifofile="/tmp/$$.fifo"
echo $tmp_fifofile
mkfifo $tmp_fifofile
exec 6<>$tmp_fifofile
rm $tmp_fifofile

thread=3
for ((i=0;i<$thread;i++));do
    echo
done >&6

for ((i=0;i<10;i++));do
    read -u6
    {
         a_sub

         echo >&6
    } &
done
wait
exec 6>&-

exit 0