【shell】并发控制测试远程主机连接

设置最高同时并发数为5
最终效果为五条五条显示

#!/usr/bin/bash
#ping01
#by racon 2022-04-21

# 同时并发数
thread=5
# 管道
tmp_fifofile=/tmp/$$.fifo

mkfifo $tmp_fifofile	# 创建管道
exec 8<> $tmp_fifofile	# 创建文件句柄
rm $tmp_fifofile		# 删除管道文件，只保留句柄

for i in `seq $thread`
do
        echo >&8
done

for i in {1..254}
do
        read -u 8
        {
        ip=192.168.220.$i
        ping -c1 -W1 $ip &> /dev/null
        if [ $? -eq 0 ];then
                echo "$ip is up."
        else
                echo "$ip is down."
        fi
        echo >&8
        }&
done
wait
exec 8>&-
echo "all finished"