move_uploaded_file函数失效求助：已排查路径与权限仍报错

Hey there, let's work through why your move_uploaded_file call is failing—you've already checked paths and permissions, so let's cover the other common culprits that might be tripping you up.

Key Checks to Fix the Issue #

1. Confirm the Temporary File is a Valid Upload #

move_uploaded_file has a strict security rule: it only moves files uploaded via HTTP POST. If your $tempN variable isn't pulled directly from $_FILES['your_input_name']['tmp_name'], the function will fail outright (even if the path looks correct).

Add this quick check to verify:

if(is_uploaded_file($tempFileName)) {
    echo "This is a valid uploaded temporary file";
} else {
    echo "Not an uploaded file—this is why move_uploaded_file is failing!";
}

Always make sure $tempFileName comes from the $_FILES superglobal, not a manually defined path.

2. Use Absolute Paths to Avoid Ambiguity #

Relative paths like "files/" can be unreliable because they depend on PHP's current working directory (which might not match your script's location). Switch to an absolute path using __DIR__ (the directory of your current PHP script) to eliminate confusion:

// Define absolute path to your target directory
$target = __DIR__ . "/files/";

// Create the directory if it doesn't exist (with proper permissions)
if(!is_dir($target)) {
    mkdir($target, 0755, true); // Recursively creates nested directories
}

// Sanitize the filename to prevent path traversal attacks
$safeFileName = basename($teste);
$fileTarget = $target . $safeFileName;

3. Double-Check Permissions for the Right User #

You mentioned checking permissions, but ensure the target directory is owned by the user running PHP (usually www-data for Apache/Nginx on Linux, or IIS_IUSRS on Windows).

On Linux, run these commands to verify and fix permissions:

# Check directory owner and permissions
ls -l files/

# Change owner to PHP's user (adjust if your server uses a different user)
sudo chown www-data:www-data files/

# Set correct permissions
sudo chmod 0755 files/

4. Get Specific Error Messages #

Right now you're only outputting "erro"—enable PHP error reporting to see exactly why the function is failing:

// Add this at the top of your script
error_reporting(E_ALL);
ini_set('display_errors', 1);

// When move_uploaded_file fails, print the last error
if(move_uploaded_file($tempFileName, $fileTarget)){
    echo "<br>I am there yeeee";
}else{
    echo "<br>erro: " . error_get_last()['message'];
}

This will show you details like "Permission denied" or "No such file or directory", which directly point to the root problem.

5. Check PHP Upload Limits #

If your file is too large, PHP might reject the upload entirely—meaning the temporary file never exists. Verify these settings in your php.ini file (or use phpinfo() to check current values):

• upload_max_filesize: Maximum size of a single uploaded file
• post_max_size: Total size allowed for POST requests (must be larger than upload_max_filesize)
• max_execution_time: Ensure this is long enough for large files to upload

Modified Working Code Example #

Here's a revised version of your code incorporating all these checks:

error_reporting(E_ALL);
ini_set('display_errors', 1);

// Replace 'your_file_input' with the name attribute from your file upload form
$uploadedFile = $_FILES['your_file_input'];

$targetDir = __DIR__ . "/files/";
if(!is_dir($targetDir)) {
    mkdir($targetDir, 0755, true);
}

$safeFileName = basename($uploadedFile['name']);
$targetPath = $targetDir . $safeFileName;
$tempFilePath = $uploadedFile['tmp_name'];

if(is_uploaded_file($tempFilePath)) {
    if(move_uploaded_file($tempFilePath, $targetPath)){
        echo "<br>I am there yeeee";
    }else{
        echo "<br>erro: " . error_get_last()['message'];
    }
} else {
    echo "<br>Error: The temporary file is not a valid uploaded file. Did the file even upload?";
}

内容的提问来源于stack exchange，提问作者Frederico Calor