php上傳文件常見問題(基礎)-php教程-PHP中文網

既然上一篇文章《php上傳中文文件檔名亂碼問題》遇到了文件上傳的問題，乾脆把php上傳文件時常碰到的幾個問題總結一下吧，以後用到時不用再去找了。

1.先做個最簡單的上傳檔案

<span> 1</span> <span><</span><span>html</span><span>></span>
<span> 2</span> <span><</span><span>head</span><span>></span>
<span> 3</span> <span><</span><span>meta </span><span>http-equiv</span><span>="Content-Type"</span><span> content</span><span>="text/html; charset=utf-8"</span><span>></span>
<span> 4</span> <span></</span><span>head</span><span>></span>
<span> 5</span> <span><</span><span>body</span><span>></span>
<span> 6</span> 
<span> 7</span> <span><</span><span>form </span><span>action</span><span>="upload_file.php"</span><span> method</span><span>="post"</span>
<span> 8</span> <span>enctype</span><span>="multipart/form-data"</span><span>></span>
<span> 9</span> <span><</span><span>label </span><span>for</span><span>="file"</span><span>></span>Filename:<span></</span><span>label</span><span>></span>
<span>10</span> <span><</span><span>input </span><span>type</span><span>="file"</span><span> name</span><span>="file"</span><span> id</span><span>="file"</span> <span>/></span> 
<span>11</span> <span><</span><span>br </span><span>/></span>
<span>12</span> <span><</span><span>input </span><span>type</span><span>="submit"</span><span> name</span><span>="submit"</span><span> value</span><span>="Submit"</span> <span>/></span>
<span>13</span> <span></</span><span>form</span><span>></span>
<span>14</span> 
<span>15</span> <span></</span><span>body</span><span>></span>
<span>16</span> <span></</span><span>html</span><span>></span>

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<span> 1</span> <?<span>php
</span><span> 2</span> <span>if</span> ((<span>$_FILES</span>["file"]["size"] < 20000<span>)
</span><span> 3</span> <span>  {
</span><span> 4</span>   <span>if</span> (<span>$_FILES</span>["file"]["error"] > 0<span>)
</span><span> 5</span> <span>    {
</span><span> 6</span>     <span>echo</span> "Return Code: " . <span>$_FILES</span>["file"]["error"] . "<br />"<span>;
</span><span> 7</span> <span>    } 
</span><span> 8</span>   <span>else</span>
<span> 9</span> <span>    {
</span><span>10</span>     <span>echo</span> "Upload: " . <span>$_FILES</span>["file"]["name"] . "<br />"<span>;
</span><span>11</span>     <span>echo</span> "Type: " . <span>$_FILES</span>["file"]["type"] . "<br />"<span>;
</span><span>12</span>     <span>echo</span> "Size: " . (<span>$_FILES</span>["file"]["size"] / 1024) . " Kb<br />"<span>;
</span><span>13</span>     <span>echo</span> "Temp file: " . <span>$_FILES</span>["file"]["tmp_name"] . "<br />"<span>;
</span><span>14</span> 
<span>15</span>     <span>if</span> (<span>file_exists</span>("upload/" . <span>$_FILES</span>["file"]["name"<span>]))
</span><span>16</span> <span>      {
</span><span>17</span>       <span>echo</span> <span>$_FILES</span>["file"]["name"] . " already exists. "<span>;
</span><span>18</span> <span>      }
</span><span>19</span>     <span>else</span>
<span>20</span> <span>      {
</span><span>21</span>       <span>move_uploaded_file</span>(<span>$_FILES</span>["file"]["tmp_name"],
<span>22</span>       "upload/" . <span>$_FILES</span>["file"]["name"<span>]);
</span><span>23</span>       <span>echo</span> "Stored in: " . "upload/" . <span>$_FILES</span>["file"]["name"<span>];
</span><span>24</span> <span>      }
</span><span>25</span> <span>    }
</span><span>26</span> <span>  }
</span><span>27</span> <span>else</span>
<span>28</span> <span>  {
</span><span>29</span>   <span>echo</span> "Invalid file"<span>;
</span><span>30</span> <span>  }
</span><span>31</span> ?>

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2.然後了解超級全域變數$_FILES的值

$_FILES['userfile']['name']

$_FILES['userfile']['type']

$_FILES['userfile']['size']

$_FILES['userfile']['tmp_name']

$_FILES['userfile']['error']

其中,$_FILES['userfile']['error']的所有值：

UPLOAD_ERR_OK 其值為 0，沒有錯誤發生，檔案上傳成功。

UPLOAD_ERR_INI_SIZE 其值為 1，上傳的檔案超過了 php.ini 中 upload_max_filesize 選項限制的值。

UPLOAD_ERR_FORM_SIZE 其值為 2，上傳檔案的大小超過了 HTML 表單中 MAX_FILE_SIZE 選項指定的值。

UPLOAD_ERR_PARTIAL 其值為 3，檔案只有部分被上傳。

UPLOAD_ERR_NO_FILE 其值為 4，沒有檔案上傳。

UPLOAD_ERR_NO_TMP_DIR 其值為 6，找不到臨時資料夾。 PHP 4.3.10 和 PHP 5.0.3 引進。

UPLOAD_ERR_CANT_WRITE 其值為 7，檔案寫入失敗。 PHP 5.1.0 引進。

3.很多情況：需要嚴格判斷上傳檔案類型

我們知道使用$_FILES['userfile']['type']判斷上傳檔案類型是一個很不明智的做法，因為該判斷依據是檔案的後綴名，任何人都可以將一個mp3檔案的後綴改成jpg從而偽裝成圖片進行上傳，因此php官方建議使用php的擴展php_fileinfo來判斷文件的mime,開啟拓展的方法百度一下有很多,win和linux略有不同。

4.情境一：上傳檔案重名後自動重新命名

<span> 1</span> <span>if</span> (<span>file_exists</span>("./upload/" . <span>$_FILES</span>["file"]["name"<span>]))  
</span><span> 2</span> <span>{    
</span><span> 3</span>    <span>do</span><span>{  
</span><span> 4</span>        <span>$suffix</span> =""<span>;  
</span><span> 5</span>        <span>$suffix_length</span> = 4<span>;  
</span><span> 6</span>        <span>$str</span> = "0123456789abcdefghijklmnopqrstuvwxyz"<span>;  
</span><span> 7</span>        <span>$len</span> = <span>strlen</span>(<span>$str</span>)-1<span>; 
</span><span> 8</span>        <span>//</span><span>文件名后追加4个随机字符  </span>
<span> 9</span>        <span>for</span>(<span>$i</span>=0 ; <span>$i</span><<span>$suffix_length</span>; <span>$i</span>++<span>){  
</span><span>10</span>           <span>$suffix</span> .= <span>$str</span>[<span>rand</span>(0,<span>$len</span><span>)];  
</span><span>11</span> <span>       }  
</span><span>12</span>        <span>$upload_filename</span> = <span>$_FILES</span>['file']['name'<span>];                                            
</span><span>13</span>        <span>$filename</span> = <span>substr</span>(<span>$upload_filename</span>,0,<span>strrpos</span>(<span>$upload_filename</span>,".")).<span>$suffix</span>.".".<span>substr</span>(<span>$upload_filename</span>,<span>strrpos</span>(<span>$_FILES</span>["file"]["name"],".")+1<span>); 
</span><span>14</span>    }<span>while</span>(<span>file_exists</span>("./upload/".<span>$filename</span><span>));  
</span><span>15</span>        <span>move_uploaded_file</span>(<span>$_FILES</span>["file"]["tmp_name"],"./upload/" . <span>$filename</span><span>);  
</span><span>16</span> }<span>else</span><span>{  
</span><span>17</span>        <span>move_uploaded_file</span>(<span>$_FILES</span>["file"]["tmp_name"], "upload/" . <span>$_FILES</span>["file"]["name"<span>]);   
</span><span>18</span> }

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5.情境二：依日期分目錄上傳檔案

<span>1</span> <span>$structure</span> = './'.<span>date</span>("Y").'/'.<span>date</span>("m").'/'.<span>date</span>("d").'/'<span>;
</span><span>2</span> 
<span>3</span> 
<span>4</span> <span>if</span> (!<span>mkdir</span>(<span>$structure</span>, 0777, <span>true</span><span>)) {
</span><span>5</span>     <span>die</span>('Failed to create folders...'<span>);
</span><span>6</span> <span>}
</span><span>7</span> 
<span>8</span> <span>move_uploaded_file</span>(<span>$_FILES</span>["file"]["tmp_name"],<span>$structure</span> . <span>$_FILES</span>["file"]["name"]);

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6.情境三：多檔案上傳

<span>1</span> <span><</span><span>form </span><span>action</span><span>=""</span><span> method</span><span>="post"</span><span> enctype</span><span>="multipart/form-data"</span><span>>
<span>2</span> <span><</span><span>p</span><span>></span><span>Pictures:
</span><span>3</span> <span><</span><span>input </span><span>type</span><span>="file"</span><span> name</span><span>="pictures[]"</span> <span>/></span>
<span>4</span> <span><</span><span>input </span><span>type</span><span>="file"</span><span> name</span><span>="pictures[]"</span> <span>/></span>
<span>5</span> <span><</span><span>input </span><span>type</span><span>="file"</span><span> name</span><span>="pictures[]"</span> <span>/></span>
<span>6</span> <span><</span><span>input </span><span>type</span><span>="submit"</span><span> value</span><span>="Send"</span> <span>/></span>
<span>7</span> <span></</span><span>p</span><span>></span>
<span>8</span> <span></</span><span>form</span><span>></span>

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<span>1</span> <?<span>php
</span><span>2</span> <span>foreach</span> (<span>$_FILES</span>["pictures"]["error"] <span>as</span> <span>$key</span> => <span>$error</span><span>) {
</span><span>3</span>     <span>if</span> (<span>$error</span> ==<span> UPLOAD_ERR_OK) {
</span><span>4</span>         <span>$tmp_name</span> = <span>$_FILES</span>["pictures"]["tmp_name"][<span>$key</span><span>];
</span><span>5</span>         <span>$name</span> = <span>$_FILES</span>["pictures"]["name"][<span>$key</span><span>];
</span><span>6</span>         <span>move_uploaded_file</span>(<span>$tmp_name</span>, "data/<span>$name</span>"<span>);
</span><span>7</span> <span>    }
</span><span>8</span> <span>}
</span><span>9</span> ?>

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有的情況下多檔案的這種變數結構並不好用：

array(1) {

["upload"]=>array(2) {

["name"]=>array(2) {

[0]=>string(9)"file0.txt"

[1]=>string(9)"file1.txt"

}

["type"]=>array(2) {

[0]=>string(10)"text/plain"

[1]=>string(10)"text/html"

}

}

}

很多情況下我們需要的是類似這樣的結構

array(1) {

["upload"]=>array(2) {

[0]=>array(2) {

["name"]=>string(9)"file0.txt"

["type"]=>string(10)"text/plain"

},

[1]=>array(2) {

["name"]=>string(9)"file1.txt"

["type"]=>string(10)"text/html"

}

}

}

使用下面的函數就能輕鬆轉換結構

<span>1</span> <span>function</span> diverse_array(<span>$vector</span><span>) { 
</span><span>2</span>     <span>$result</span> = <span>array</span><span>(); 
</span><span>3</span>     <span>foreach</span>(<span>$vector</span> <span>as</span> <span>$key1</span> => <span>$value1</span><span>) 
</span><span>4</span>         <span>foreach</span>(<span>$value1</span> <span>as</span> <span>$key2</span> => <span>$value2</span><span>) 
</span><span>5</span>             <span>$result</span>[<span>$key2</span>][<span>$key1</span>] = <span>$value2</span><span>; 
</span><span>6</span>     <span>return</span> <span>$result</span><span>; 
</span><span>7</span> <span>} 
</span><span>8</span> <span>$upload</span> = diverse_array(<span>$_FILES</span>["upload"]);

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7. 有的時候：需要設定伺服器修改最大上傳檔案大小

首先，在表單上

<span><</span><span>input </span><span>type</span><span>="hidden"</span><span> name</span><span>="MAX_FILE_SIZE"</span><span> value</span><span>="字节"</span> <span>/></span>

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可以限制上傳檔案大小（可以被繞過）。

然後在伺服器上也需要調整一下設定

php.ini:

max_execution_time = 30 每个脚本运行的最长时间，单位秒
max_input_time = 60，每个脚本可以消耗的时间，单位也是秒
memory_limit = 128M，这个是脚本运行最大消耗的内存
post_max_size = 8M，表单提交最大数据为 8M，此项不是限制上传单个文件的大小,而是针对整个表单的提交数据进行限制的。
upload_max_filesize = 2M ，上载文件的最大许可大小

nginx:

<span>1</span> <span>location / {
</span><span>2</span>     root   html<span>;
</span><span>3</span>     index  index.html index.htm<span>;
</span><span>4     </span>client_max_body_size    1000m<span>;
</span><span>5</span>  }

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以上就介绍了php上传文件常见问题(基础)，包括了方面的内容，希望对PHP教程有兴趣的朋友有所帮助。