[PHP][轉] PHP檔案上傳－碎碎念

http://php5.idv.tw/html.php?mod=article&do=show&shid=6

最近常常碰到檔案上傳，乾脆整理一下並且弄清楚，免得之後要用都要再找。

PHP上传实例

上传档案的网页

<form enctype="multipart/form-data" action="__URL__" method="POST">
    
    <input type="hidden" name="MAX_FILE_SIZE" value="30000" />
    
    Send this file: <input name="userfile" type="file" />
    <input type="submit" value="Send File" />
</form>

p.s. 重點

* form要加上 enctype="multipart/form-data"才能上傳檔案

* 上傳檔案的input type要設為file

接收参数阵列
档案名称
$_FILES['userfile']['name']

档案格式(image/jpeg)
$_FILES['userfile']['type']

档案大小
$_FILES['userfile']['size']

档案暂存的位置(伺服器上暂存的位置,必须要移动到正确的位置)
$_FILES['userfile']['tmp_name']

错误讯息
$_FILES['userfile']['error']

P.s. $_FILE['xxxxx']裡頭的xxxxx取決於你form裡頭選擇檔案input的"name"

使用到PHP 的 move_uploaded_file 函式

bool move_uploaded_file(source file, target file);

即是將source file搬移到target file(名稱可自訂), 搬移完成後再將原檔案刪除.

如windows中的剪下貼上.

如搬移成功則回傳true, 失敗則回傳false

语法例:

<?php
// In PHP versions earlier than 4.1.0, $HTTP_POST_FILES should be used instead
// of $_FILES.

$uploaddir = '/var/www/uploads/';
$uploadfile = $uploaddir . basename($_FILES['userfile']['name']);

echo '<pre>';
if (move_uploaded_file($_FILES['userfile']['tmp_name'], $uploadfile)) {
   echo "File is valid, and was successfully uploaded.\\\\n";
} else {
   echo "Possible file upload attack!\\\\n";
}

echo 'Here is some more debugging info:';
print_r($_FILES);

print "</pre>";

?>
多档同时传送阵列实例



<form action="" method="post" enctype="multipart/form-data"> 
<p>Pictures: <input type="file" name="pictures[]" /> 
<input type="file" name="pictures[]" /> <input type="file" name="pictures[]" /> 
<input type="submit" value="Send" /> 
</p> </form>
<?php
foreach ($_FILES["pictures"]["error"] as $key => $error) {
   if ($error == UPLOAD_ERR_OK) {
     $tmp_name = $_FILES["pictures"]["tmp_name"][$key];
     $name = $_FILES["pictures"]["name"][$key];
     move_uploaded_file($tmp_name, "data/$name");
   }
}
?>

PHP，檔案上傳

雖然檔案上傳已經不是新鮮事了，但是總覺得自己寫的應該比較容易看得懂，遇到問題要討論也比較方便一些。

一、前置作業

PHP 檔案上傳運作原理
PHP 上傳檔案時會先將檔案移到暫存目錄，上傳成功後再將檔案送往上傳目錄並自動清除暫存檔

php.ini 檔案上傳相關設定

; Whether to allow HTTP file uploads. 檔案上傳，預設為開啟
file_uploads = On

; Temporary directory for HTTP uploaded files (will use system default if not
; specified). PHP 暫存目錄設定，預設為系統暫存目錄，若需設定請將前置分號移除
;upload_tmp_dir =

; Maximum allowed size for uploaded files. PHP 預設上傳限制為 2M
upload_max_filesize = 2M

二、檔案上傳示範 (big5)

file.htm

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=big5">
<title>檔案上傳</title>
</head>
<body>
<form action="file_ok.php" method="post" enctype="multipart/form-data">
<input type="hidden" name="max_file_size" value="1024000">
<input type="file" name="myfile">
<input type="submit" value="上傳">
</form>
</body>
</html>

1. 範例檔案為 big5 編碼，因 utf-8 編碼有中文檔案名上傳問題，之後再討論。
2. 上傳檔案時，form 的 enctype 屬性要設定為 multipart/form-data
3. <input type="hidden" name="max_file_size" value="1024">
可限定上傳檔案大小（1k = 1024），要寫在 <input type="file" ... > 之前

file_ok.php

<?php
$uploaddir = '';
$uploadfile = $uploaddir.basename($_FILES['myfile']['name']);

echo "<pre>";
if (move_uploaded_file($_FILES['myfile']['tmp_name'], $uploadfile)) {
    echo "Upload OK \n";
} else {
    echo "Upload failed \n";
}
print_r($_FILES);
echo "</pre>";
?>

1. PHP 4.1 之前版本，要用 $HTTP_POST_FILES 取代 $_FILES
2. $uploaddir 為上傳目錄設定。
3. 移除檔案可使用 unlink() 函數，例 unlink($uploaddir.$uploadfile);

三、注意事項

UTF-8 的中文檔案名上傳問題
utf-8 編碼網頁無法在 big5 系統正確處理中文檔名，原因在於 move_uploaded_file() 不能處理 utf-8 中文編碼，需利用 iconv() 函數作轉碼，解決方法如下：

請將

move_uploaded_file($_FILES['myfile']['tmp_name'], $uploadfile)

改為

move_uploaded_file($_FILES['myfile']['tmp_name'], iconv("utf-8", "big5", $uploadfile))

四、檔案上傳示範 (utf-8)

file.htm

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>檔案上傳</title>
</head>
<body>
<form action="file_ok.php" method="post" enctype="multipart/form-data">
<input type="hidden" name="max_file_size" value="102400000">
<input type="file" name="myfile">
<input type="submit" value="上傳">
</form>
</body>
</html>

file_ok.php

<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<?php
$uploaddir = '';
$uploadfile = $uploaddir.basename($_FILES['myfile']['name']);

echo "<pre>"; if (move_uploaded_file($_FILES['myfile']['tmp_name'], iconv("utf-8", "big5", $uploadfile))) { echo "Upload OK \n"; } else { echo "Upload failed \n"; } print_r($_FILES); echo "</pre>"; ?>