shell请教read,wait控制多线程

illfar

现在有一个例子，但是跑下来发现，程序无法结束，或者说退出
请高手指点

代码
# !/bin/bash

function a_sub {
sleep 3
}


tmp_fifofile="/tmp/$$.fifo"
mkfifo $tmp_fifofile
exec 6<>$tmp_fifofile
rm $tmp_fifofile


thread=5
for((i=0;i<$thread;i++)); do
echo >&6
done&


for((i=0;i<11;i++ )); do
read -u6
{
        a_sub && {
        echo " a_sub is finished "
        } || {
        ech " sub error "
        }
        echo >&6
}&

done

wait
exec 6>&-


exit 0



sh -x 的结果如下：

$ sh -x sample.sh
+ tmp_fifofile=/tmp/7300.fifo
+ mkfifo /tmp/7300.fifo
+ exec
+ rm /tmp/7300.fifo
+ thread=5
+ (( i=0 ))
+ (( i<5 ))
+ echo
+ (( i++ ))
+ (( i<5 ))
+ echo
+ (( i=0 ))
+ (( i<11 ))
+ read -u6
+ (( i++ ))
+ (( i<5 ))
+ echo
+ a_sub+ (( i++ ))

+ sleep 3
+ (( i<11 ))
+ read -u6
+ (( i++ ))
+ (( i<5 ))
+ echo
+ a_sub
+ sleep 3
+ (( i++ ))
+ (( i<11 ))
+ read -u6
+ (( i++ ))
+ (( i<5 ))
+ echo
+ (( i++ ))
+ (( i<11 ))
+ read -u6
+ a_sub
+ sleep 3
+ (( i++ ))
+ (( i<5 ))
+ (( i++ ))
+ (( i<11 ))
+ read -u6
+ a_sub
+ sleep 3
+ (( i++ ))
+ (( i<11 ))
+ a_sub
+ read -u6
+ sleep 3
+ echo ' a_sub is finished '+ echo ' a_sub is finished '

a_sub is finished
a_sub is finished
+ echo
+ echo
+ (( i++ ))
+ a_sub
+ (( i<11 ))
+ sleep 3
+ read -u6
+ (( i++ ))
+ (( i<11 ))+ a_sub

+ sleep 3
+ read -u6
+ echo ' a_sub is finished '
a_sub is finished
+ echo ' a_sub is finished '
+ echo
a_sub is finished
+ echo
+ (( i++ ))
+ (( i<11 ))
+ a_sub
+ read -u6
+ sleep 3
+ (( i++ ))
+ (( i<11 ))
+ read -u6
+ a_sub
+ sleep 3
+ echo ' a_sub is finished '
a_sub is finished
+ echo
+ a_sub
+ sleep 3+ (( i++ ))

+ (( i<11 ))
+ read -u6
+ echo ' a_sub is finished '
a_sub is finished
+ echo
+ echo ' a_sub is finished '
a_sub is finished
+ echo
+ a_sub
+ (( i++ ))
+ sleep 3+ (( i<11 ))

+ wait
+ echo ' a_sub is finished '
a_sub is finished
+ echo
+ echo ' a_sub is finished '
a_sub is finished
+ echo
+ echo ' a_sub is finished '
a_sub is finished
+ echo
+ echo ' a_sub is finished '
a_sub is finished
+ echo
这里停止了

waker

thread=7

illfar

回复 2# waker


    什么意思啊
应该如何修改阿

illfar

thread=1的话，就没有问题了

为什么阿

illfar

回复 5# Honey-pot

可惜，猜错了