What is the ranking query principle on webmaster tools? How can this problem be solved?

What is the ranking query principle on webmaster tools? URL: http://tool.chinaz.com/keywords/he can check up to hundred-degree snapshots each time (10 pages per page, that is, 10 pages). If you use file_get_contents to read the webpage each time and then perform regular matching, what is the principle of ranking query on 100 webmasters at a time?
Web: http://tool.chinaz.com/KeyWords/

He can query up to 100 Baidu snapshots (10 on one page, that is, 10 pages) at a time. if he reads the webpage with file_get_contents each time and then matches the regular expression, one query of 100 million, that is, one file_get_contents Baidu 10 pages, the speed will be very slow, but why is the speed of this webmaster station so fast? What principles are used? More than one station has this function, and many webmasters have it. I think Baidu will certainly not provide him with api interfaces! Why is his principle so fast?

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You can view the first 100 records at a time without using APIs.
For example, to query csdn url rules: www.baidu.com/s? Wd = csdn
After adding the parameter & rn = 100, you can see the first 100 records, such as www.baidu.com/s? Wd = csdn and rn = 100
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Extract 100 entries, and then extract the regular expression.