php 图片上传目录

$allowed_types = array('image/jpeg', 'image/png', 'image/gif');
if (in_array($_FILES['image']['type'], $allowed_types)) {
    // 文件类型允许，继续处理上传
} else {
    // 文件类型不允许，返回错误信息
    echo "Invalid file type.";
}

<?php
$target_dir = "uploads/";
$target_file = $target_dir . basename($_FILES["image"]["name"]);
$uploadOk = 1;
$imageFileType = strtolower(pathinfo($target_file,PATHINFO_EXTENSION));

// 检查文件是否为图片
if(isset($_POST["submit"])) {
    $check = getimagesize($_FILES["image"]["tmp_name"]);
    if($check !== false) {
        echo "File is an image - " . $check["mime"] . ".";
        $uploadOk = 1;
    } else {
        echo "File is not an image.";
        $uploadOk = 0;
    }
}

// 检查文件是否已经存在
if (file_exists($target_file)) {
    echo "Sorry, file already exists.";
    $uploadOk = 0;
}

// 检查文件大小
if ($_FILES["image"]["size"] > 500000) {
    echo "Sorry, your file is too large.";
    $uploadOk = 0;
}

// 允许特定文件格式
if($imageFileType != "jpg" && $imageFileType != "png" && $imageFileType != "jpeg"
&& $imageFileType != "gif" ) {
    echo "Sorry, only JPG, JPEG, PNG & GIF files are allowed.";
    $uploadOk = 0;
}

// 检查是否设置了$uploadOk标志
if ($uploadOk == 0) {
    echo "Sorry, your file was not uploaded.";

// 如果一切正常，尝试上传文件
} else {
    if (move_uploaded_file($_FILES["image"]["tmp_name"], $target_file)) {
        echo "The file ". htmlspecialchars( basename( $_FILES["image"]["name"])). " has been uploaded.";
    } else {
        echo "Sorry, there was an error uploading your file.";
    }
}
?>