来了一个域名如何判断其缓存与否，高大上的专业爬虫当然可以做分析，如果不是很严谨的分析，通过shell脚本也可以实现，来看看我这个一层页面的小爬吧，哈哈哈，先脚本执行后的结果图：
在处理的时候，会用elinks把页面上所有的元素爬出来，并做统计，用curl探测头信息，通过cache-control头来做判断是否可缓存，如果一个域名下超过70%的url可缓存，那么我就简单认为这个host是可以缓存的，虽然比较粗糙，但是做一个粗略的参考和学习应该足够。
脚本程序如下：
#/bin/sh
#### 分析域名一级页面元素的可缓存的情况###############
#writer:gaolixu
showprint(){
tput clear
echo -e `tput bold`"The web has the url host is(more than 70% item can be cache is yes):"
echo -e `tput bold;tput setaf 1;`"Times\tHost\t\t\t\tIp\t\t\t\t\t\t\tyes%\t\tno%\t\tunknown%\tCache(yes/no)"
tput sgr0
i=2
cat /tmp/cachetest/cache.test |awk -F‘+‘ ‘{print $1}‘ |sort|uniq -c |sort -nr |
while read url
do
url_host=`echo $url |awk ‘{print $2}‘`
url_yes=`cat /tmp/cachetest/cache.test|egrep $url_host 2>/dev/null |awk -F‘+‘ ‘{print $5}‘|egrep -c yes`
url_no=`cat /tmp/cachetest/cache.test|egrep $url_host 2>/dev/null |awk -F‘+‘ ‘{print $5}‘|egrep -c no`
url_unknown=`cat /tmp/cachetest/cache.test|egrep $url_host 2>/dev/null |awk -F‘+‘ ‘{print $5}‘|egrep -c unknown`
((url_sum=url_yes+url_no+url_unknown))
url_yes_b=`awk -v url_yes=$url_yes -v url_sum=$url_sum ‘BEGIN{printf "%.1f", url_yes/url_sum*100}‘`
url_no_b=`awk -v url_no=$url_no -v url_sum=$url_sum ‘BEGIN{printf "%.1f", url_no/url_sum*100}‘`
url_unknown_b=`awk -v url_unknown=$url_unknown -v url_sum=$url_sum ‘BEGIN{printf "%.1f", url_unknown/url_sum*100}‘`
url_ip=`cat /tmp/cachetest/cache.test|egrep $url_host 2>/dev/null |head -1|awk -F‘+‘ ‘{print $3}‘`
url_status=`awk -v url_yes_b=$url_yes_b ‘BEGIN{if (url_yes_b>70) print "yes";else print "no"}‘`
echo -n -e "$url"|sed ‘s/ /\t/‘
tput cup $i 40
echo -n "$url_ip"
tput cup $i 96
echo -n "$url_yes_b%"
tput cup $i 112
echo -n "$url_no_b%"
tput cup $i 128
echo "$url_unknown_b%"
tput cup $i 144
echo "$url_status"
((i+=1))
done
}
host $1 &>/dev/null || { echo "The url is error,can‘t host!!";exit;}
mkdir /tmp/cachetest &> /dev/null
[ -f /tmp/cachetest/cache.test ] && rm /tmp/cachetest/cache.test
num=`elinks --dump $1 |egrep $2|sed ‘/http:/s/http:/\nhttp:/‘|awk -F‘[/|,]‘ ‘/^http/{print $0}‘ |sort|wc -l`
echo `tput bold`"The sum links is $num!!"
echo `tput bold`"The analysis is running..."
tput sgr0
elinks --dump $1 |egrep $2|sed ‘/http:/s/http:/\nhttp:/‘|awk -F‘[/|,]‘ ‘/^http/{print $0}‘ |sort|
while read url
do
url_host=`echo $url|awk -F‘[/|,]‘ ‘/^http/{print $3}‘`
url_url=`echo $url|sed "s/$url_host/\t/"|awk ‘{print $2}‘`
url_ip=`host $url_host | egrep address |awk ‘{print $NF}‘|sed ‘{1h;1!H;$g;$!d;s/\n/\//g}‘`
cc=`curl -s -I -m 3 $url |egrep Cache-Control|head -1|egrep Cache-Control|sed ‘{1h;1!H;$g;$!d;s/\n/ /g}‘`
if [ "$cc" ];then
cc_n=${#cc}
((cc_n-=1))
cc=`echo $cc|cut -b1-$cc_n`
else
cc="no cache-control flags or time out"
fi
cc_i=`echo $cc |sed ‘s/max-age=/\n/‘|awk -F"[,| ]" ‘NR==2{print $1}‘`
if echo $cc|egrep no-cache &>/dev/null || echo $cc|egrep no-store &>/dev/null;then
cc_status="no"
elif [[ $cc_i = 0 ]];then
cc_status="no"
elif [[ $cc_i > 0 ]];then
cc_status="yes"
else
cc_status="unknown"
fi
echo -e "$url_host+$url_url+$url_ip+$cc+$cc_status" >> /tmp/cachetest/cache.test
echo -n "#"
done
sleep 2
(showprint)本文出自 “奔跑的linux” 博客，请务必保留此出处http://benpaozhe.blog.51cto.com/10239098/1747543
原文地址：http://benpaozhe.blog.51cto.com/10239098/1747543
