#ping三次终止
ping -c 3 www.baidu.com
#5秒钟后停止ping操作
ping -w 5 www.baidu.com
指定ping包1024bytes
ping -s 1024 www.baidu.com

yum list all | grep 'hping'

yum install -y hping3

#对方来讲显然是一种攻击行为,如果对baidu是hping不了的
hping --fast 127.0.0.1

#安装ftp客户端
yum install ftp -y

#安装lftp
yum install -y lftp
#-u指明用户名zhangsan来访问ftp服务器
lftp -u zhangsan 172.16.0.1

#-u 用户名,密码的方式来访问ftp服务器
lftp -u zhangsan,123456 172.16.0.1

lftpget http://fastsoft.onlinedown.net/down/idm_ald.exe

#直接下载
wget http://fastsoft.onlinedown.net/down/idm_ald.exe
#指定保存目录和文件名
wget http://fastsoft.onlinedown.net/down/idm_ald.exe -O /tmp/abc.exe

#查找软件包
yum list | grep rz
yum search rz
#安装
yum install -y lrzsz.x86_64
#选择文件上传
rz
#下载指定目录的文件
sz ~/love.abc

curl http://www.baidu.com
#设置用户代理发送给服务器,在/var/log/httpd/access.log下查看该访问的用户代理
curl -A "chrome10.11"  http://192.168.147.152
curl --user-agent "chrome10.12"  http://192.168.147.152

#设置referer来源网址
curl --user-agent "chrome10.12" -e "https://www.google.com/search?q=hello"  http://192.168.147.152

#只显示响应报文首部信息
curl -I http://192.168.147.152

elinks http://www.baidu.com
elinks -dump  http://www.baidu.com

#!/bin/bash

declare -i i=0
declare -i sum=0

while [ $i -le 100 ];do
     sum=$[$sum+$i] 
     let i++
done

echo $sum

#!/bin/bash

while read line;do
   userid=$(echo $line | cut -d: -f3)
   username=$(echo $line | cut -d: -f1)
   shell=$(echo $line | cut -d: -f7)

   if [ $[ $userid % 2 ] -eq 0 ];then
      echo "$userid,$username,$shell"
   fi
done < /etc/passwd

#!/bin/bash

declare -i sum=0;
declare -i i=0;

until [ $i -gt 100 ];do
    let sum+=$i
    let i++
done

echo $sum

#!/bin/bash  

declare -i evenSum=0
declare -i i=0

[ $# -lt 1 ] && echo "请输入计算偶数的上线的数值!" && exit 1

while [ $i -le $1 ];do
    let i++
    if [ $[ $i % 2 ] -eq 1 ];then
       continue
    fi
    let evenSum+=$i
done

echo "evenSum:${evenSum}"

#!/bin/bash

[ $# -lt 1 ] && echo "请输入求奇数值上限值!" && exit 1

declare -i i=0
declare -i oddSum=0

while  true ;do
   let i++
   if [ $i -eq $1 ];then
      break;
   fi

   if [ $[ $i % 2 ] -eq 0 ];then
      continue;
   fi

   let oddSum+=$i
done

echo "oddSum:${oddSum}"

#!/bin/bash


[ $# -lt 1 ] && echo "请输入求奇数值上限值!" && exit 1

declare -i i=1
declare -i oddSum=0

while true;do
   let oddSum+=$i
   let i+=2
   if [ $i -gt $1 ];then
      break
    fi
done

echo "oddSum:${oddSum}"

#!/bin/bash

for i in {1..9};do
    for j in $(seq 1 $i);do
        echo -e -n "${j}x${i}=$[${j}*${i}]\t"
    done
       echo
done 

#!/bin/bash

while true;do
   sleep 3
   who | grep "^logstash\>" &> /dev/null && echo "$(date "+%F %T") logstash logged on" >> ~/script/log && break
done

#!/bin/bash

while true;do
   sleep 3
   if who | grep "^logstash\>" &> /dev/null;then
      break
   fi
done

echo "$(date "+%F %T") logstash logged on" >> ~/script/log

#!/bin/bash

until who | grep "^logstash\>" &> /dev/null;do
      sleep 3
done

echo "$(date "+%F %T") logstash logged on" >> ~/script/log