shell脚本实现多进程并发

#!/usr/bin/env bash

for i in {1..255}                   	#定义ip的范围
  do
	ip=118.25.100.$i                #定义ip的网段
	ping -c1 -W1 $ip &> /dev/null   #ping一次,超时时间1秒
	if [ $? -eq 0 ]                 #如果ping通了就输出下面内容
	  then
		echo "$ip is alive..."
	fi
  done

[root@test-000 shell]# time bash normal.sh 
118.25.100.3 is alive...
118.25.100.5 is alive...
118.25.100.7 is alive...
118.25.100.8 is alive...
118.25.100.9 is alive...
........................
........................
........................
........................
118.25.100.246 is alive...
118.25.100.247 is alive...
118.25.100.249 is alive...
118.25.100.250 is alive...
118.25.100.252 is alive...
118.25.100.254 is alive...

real	2m11.793s
user	0m0.416s
sys	0m1.058s

#!/usr/bin/env bash
for i in {1..255}
  do
	{
	  ip=118.25.100.$i
	  ping -c1 -W1 $ip &> /dev/null
	  if [ $? -eq 0 ]
		then
		  echo "$ip is alive..."
	  fi
	}&
  done
wait    #该命令是等待前面所有后台程序执行完毕
echo "all of finished..."

[root@test-000 shell]# time bash normal.sh 
118.25.100.50 is alive...
118.25.100.17 is alive...
118.25.100.51 is alive...
118.25.100.42 is alive...
118.25.100.20 is alive...
118.25.100.47 is alive...
.........................
.........................
.........................
.........................
.........................
118.25.100.225 is alive...
118.25.100.219 is alive...
118.25.100.254 is alive...
118.25.100.229 is alive...
118.25.100.249 is alive...
118.25.100.246 is alive...
118.25.100.252 is alive...
all of finished...

real	0m1.901s
user	0m0.181s
sys     0m0.825s

#!/usr/bin/env bash

for i in {1..65535}    #并发数量为65535
  do
	{
	  tcping 118.25.100.250 $i |grep open
	}&
  done
wait
echo "all of finished..."

[root@test-000 shell]# time bash normal.sh 
118.25.100.250 port 88 open.
118.25.100.250 port 25 open.
118.25.100.250 port 110 open.
118.25.100.250 port 3389 open.
118.25.100.250 port 10080 open.
#在这里我强行终止了程序,因为实在是太卡了!
real	11m57.992s
user	2m15.443s
sys     7m11.092s

#!/usr/bin/env bash
                              #感兴趣的请自行百度"文件描述符"和"管道文件",这里不做解释
fifo_file=/tmp/$$_fifofile    #定义管道文件路径
mkfifo $fifo_file             #创建管道文件
exec 54<> $fifo_file          #打开这个管道文件
rm -rf $fifo_file             #删除这个管道文件

for i in {1..10}              #并发的数量10个,"seq 1 10"等同于"{1..10}",前者可以使用变量赋值
  do
	echo >&54             #向管道文件里丢数据
  done

for i in {1..65535}           #定义任务数量
  do
	read -u 54            #从管道文件里读取文件,读取到内容就向下走,读取不到就停留等待
	{
	  tcping -t1 118.25.100.250 $i
	}&
	echo >&54             #由于管道文件的数据拿一个少一个,所以我们要把数据再还给管道文件
  done
wait                          #等待所有后台任务执行完毕
exec 54<&-                    #释放之前被删除的管道文件
echo "all of finished..."

[root@test-000 shell]# bash normal.sh 
118.25.100.250 port 25 open.
118.25.100.250 port 88 open.
118.25.100.250 port 110 open.
118.25.100.250 port 41 user timeout.
118.25.100.250 port 32 user timeout.
118.25.100.250 port 38 user timeout.
118.25.100.250 port 44 user timeout.
118.25.100.250 port 45 user timeout.
118.25.100.250 port 35 user timeout.
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