1. get a URL as an argument in a command line
2. print the Google popularity rank for that website (number of links pointing to this website according to Google)
3. print websites IP address(es)
4. print MX records for that domain if any
5. print website and network owner information


1.没问题
OK
2.不理解.popularity rank指在程序中嵌入google并搜索出指定URL的结果吗?如何嵌入GOOGLE到程序中去?或者说如何POST?
You may run system a "CURL" to get the result, "wget" can also do it
If you want to run native C and don't want to system external program,
you can use CURL.lib for C

3.如果通过第2步得到了多个结果,通过在程序中嵌入system执行ping,再解析PING的输出得到IP地址.好象这么做太麻烦.
There is a function called gethostbyname()

4.我写过一个程序库,虽然麻烦,可以得到MX记录.但我一直怀疑有函数可以直接获取MX记录,而自己没找到捷径.
easy to run system nslookup -q=mx "URL" and parse the output

5.不太明白.只是打印出来所有结果?
That is for using whois, the same as above, print out whois result