shell脚本实现多进程并发

#!/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

real	2m11.793s

#!/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
echo "all of finished..."

real	0m1.901s

#!/usr/bin/env bash

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

#!/usr/bin/env bash

fifo_file=/tmp/$$_fifofile
mkfifo $fifo_file
exec 54<> $fifo_file
rm -rf $fifo_file

# 控制并发数量为 10
for i in {1..10}
  do
    echo >&54
  done

# 任务数量 65535
for i in {1..65535}
  do
    read -u 54
    {
      tcping -t1 118.25.100.250 $i
    }&
    echo >&54
  done
wait
exec 54<&-
echo "all of finished..."