Some questions about file_get_content ('php://input') and $_ POST,post and put?

the day before yesterday, when I was doing a function, I found that the value of the page ajax was too much, so that both $_ POST and php://input were empty, which was very strange.

so I did a demo test to find out why:

    <script>

        var data = "username=111&email=222";
        for (var i = 0; i < 1750; iPP)
        {
            data += "&a" + i + "=" + i;
        }

        var xhr = new XMLHttpRequest();
        xhr.open("post", "./test.php");
        // xhr.open("put", "./test.php");
        xhr.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
        // xhr.setRequestHeader("Content-type", "application/json;charset=utf-8");
        // data = JSON.stringify({a: data});

        xhr.onload = function () { console.log(xhr.responseText); }
        xhr.send(data);

    </script>

because both method and Content-type feel right, but why can"t they get the value?

this problem occurs when I change application/json and application/x-www-form-urlencoded.

and there seems to be a critical value. You can see the print data in the loop 1650 in the code, and it will be empty for 1750 times. Test.php is just a simple

$content = file_get_contents("php://input");

// print_r(count($_POST) . "\n");
print_r($content);

I am a little puzzled. I keep google, Baidu for information and know the post method. There are instructions in php.ini to limit the number and size of parameters passed.

but I am the duck of file_get_contents ("php://input"), and the php input stream is not affected by php.ini profile instructions.

Why can it be done with less loops and not with more loops? Error_reporting (- 1) also reported no error, no warning, no clue.

later, I changed the request method of ajax to PUT, and found something (I didn"t understand the difference between post and put at this time)

warning

temporary1749

PHP

bug

apacheerror_log

Warningajaxpost

postbufferdiscard print_r

chmod 777 /tmp

temp

postContent-typeapplication/x-www-form-urlencoded1750

$_POSTpost_max_size8mmax_input_vars1000PHP

file_get_content("php://input")php://input

put$_POSTfile_get_content("php://input")

post16501750discard

put16501750file_get_contentsWarning

I haven"t completely cleared the reason why this happened. Guess so,

file_get_content ("php://input"), you can get data from all input streams without being affected by the php.ini instruction, but when you use this function to get content,
has two main points:
1.file_get_contents requires permission to write to temporary files
2. There is a set value for the obtained content size (specific number, or profile control, not understood). When the content size exceeds this value, the rest of the content will be written to a temporary file.

Why did this happen?

learn the difference between post and put, probably based on the semantic nature of the restful specification.

do not understand the reason for this =

Php

Jan.08,2022