PHP: download complete html code from url (with closed tags) [duplicate]

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• How to scrape ajax calls in PHP 2 answers

My problem is, that I want to download the html source code from url to a string or a file (that does not matter). I tried that with the "file_get_contents()" function, but when I try this, I am just getting parts of the code... There is a tag, which I can expand, but in code the tag is closed. How can I get this closed tag?