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网站监控

tag-icon • tag-icon shell-script
网站监控

我试图实现的目标是从网站中提取 HTML 代码，并将其写入文件。完成此操作后，我想循环它再次执行并将其写入另一个文件。写入第二个文件后，我希望它将两个文件进行比较，看看是否有任何更改。这是我到目前为止所拥有的，但它不起作用：

#!/bin/bash
echo "Hopefully this will do everything at once!"

while true;
do 

wget -q -O - http://website.com > websitebaseline.txt

if -e websitebaseline.txt
then
    wget -q -O - http://www.website.com > websitechange.txt
    echo "Update to websitechange.txt has been made"

    if !-e websitebaseline.txt
    then
        wget -q -O - http://www.website.com > webbaseline.txt
        echo "Baseline has been created"

if -e websitebaseline.txt websitechange.txt
then diff -y websitebaseline.txt websitechange.txt --supress-common-lines > Changeinsite.txt
    if !-e websitebaseline.txt
    then 
        wget -q -O - http://www.website.com > websitebaseline.txt   echo "Baseline has been created"
    elif !-e websitechange.txt
    then
        wget -q- O - http://websitename.com > websitenamechange.txt
        echo "Update has been made"

sleep 100;
done

答案1

让事情变得过于复杂。

#!/bin/bash
left=$(mktemp)
right=$(mktemp)
url="http://url.example.com/"
trap 'rm -f "$left" "$right"' EXIT
for file in "$left" "$right"; do
    wget -q -O "$file" "$url"
done
if diff "$left" "$right" > /dev/null 2>&1; then
    echo "Changes detected in successive retrievals of '$url'."
fi

可以使用类似的机制来逐步记录随时间的变化：

left=$(mktemp)
right=$(mktemp)
url="http://url.example.com/"
trap 'rm -f "$left" "$right"' EXIT
# Establish the "baseline":
wget -q -O "$left" "$url"

# Okay, now check for updates forever:
while sleep 30; do
    wget -q -O "$right" "$url"
    if diff "$left" "$right" > /dev/null 2>&1; then
        echo "$(date) - Changes detected in '$url'."
        cp "$right" "$left"
    fi
done

答案2

检测两个文件之间差异的最简单方法（无论变化有多小）就是比较它们的校验和。为了在这里演示，我只是使用“md5sum”命令来生成每个请求的 md5 哈希值。

#!/bin/bash

wget -q website.com -O site.txt
baseline=$(md5sum site.txt)
echo first request checksum: $baseline
rm site.txt

wget -q website.com -O site.txt
change=$(md5sum site.txt)
echo second request checksum: $change
rm site.txt

该脚本的输出将是每个请求的 md5 哈希值，您可以轻松查看哈希值是否相同或不同。

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