我如何使用 php 访问 cgi 网页的特定外部页面

Question

I'm trying to calculate the average rainfall on a tuesday in 2014 so far vs other days.

http://www.knmi.nl/klimatologie/daggegevens/index.cgi has all the information needed, the only problem is that each day can not be accessed with a direct link. An on-screen form has to be used to select a day.

Is there a way to automatically download these pages or the information on these pages with php?

EDIT: to be clear: I need all days from 2014, a day can be selected using the on-screen form.

I have no experience with cgi whatsoever.

Answer 1

Yes there is a way and it has nothing to do with cgi. Regardless of the programming language used to build the site; realistically you are only interested in the output of the page, which is going to tbe html in this case.

Use:

$site_html = file_get_contents('http://www.knmi.nl/klimatologie/daggegevens/index.cgi');

Now $site_html variable has the html output of the given page; you just need to parse it to get the values you want. I believe this is known as scraping web page.