创建HTML表单使用POST方法提交数据到PHP脚本；2. PHP通过$_POST接收并处理数据，进行验证和过滤；3. 使用cURL在PHP中编程发送POST请求至API；4. 通过enctype="multipart/form-data"实现文件上传，PHP用$_FILES处理。

To send data securely to a server for processing, using PHP with POST requests is a common approach. This guide walks through implementing POST requests in PHP, particularly in the context of form handling.

The operating environment of this tutorial: MacBook Pro, macOS Sonoma

1. Create an HTML Form to Submit Data via POST

This method uses a standard HTML form that sends user input to a PHP script using the POST method. The form defines where and how the data should be submitted.

• Create a file named form.html
• Use the method="post" attribute to ensure data is sent securely without appearing in the URL
• Set the action attribute to point to your PHP processing script

Example code:

  Name:
  

  Email:
  

  Submit

2. Process POST Data Using PHP

The receiving PHP script retrieves the submitted form data using the $_POST superglobal array. This array holds all data sent via the POST method.

• Create a file named process.php
• Access values using $_POST['fieldname']
• Validate and sanitize inputs before use

Example code:

echo "Hello, $name. We've received your email: $email.";

} ?>

3. Send POST Requests Programmatically Using cURL

cURL allows sending HTTP POST requests from within PHP scripts, useful when interacting with APIs or submitting data to external services.

• Initialize a cURL session with curl_init()
• Set options like URL, POST fields, and headers using curl_setopt()
• Execute the request and capture the response

Example code:

 'john', 'token' => 'abc123'];
$ch = curl_init($url);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($data));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$response = curl_exec($ch);
if (curl_error($ch)) { echo 'cURL error: ' . curl_error($ch); }
curl_close($ch);
echo $response;
?>

4. Handle File Uploads via POST in PHP

When uploading files, the form must use enctype="multipart/form-data" and the PHP script must access the $_FILES superglobal to process uploaded files.

• Add enctype="multipart/form-data" to the form tag
• Use an input with type="file" and name attribute
• Check for upload errors and move the file to a permanent location

Example code:

  
  Upload


if (move_uploaded_file($_FILES["avatar"]["tmp_name"], $targetFile)) {
    echo "The file ". htmlspecialchars(basename($_FILES["avatar"]["name"])) . " has been uploaded.";
} else {
    echo "Sorry, there was an error uploading your file.";
}
}
?>