无法获取图像文件扩展名 [英] Not able to get image file extension

问题描述

我正在使用Uploadify将图像上传到服务器.
图像已上传，并放置在Web服务器的temp文件夹中.

I'm using Uploadify to upload an image to the server.
The image is uploaded, and placed in the temp folder of the web server.

现在，我需要处理文件beore并将其移动到实际位置，并且我有以下代码:

Now I need to work with the file beore moving it to it's real location, and I have the following code:

// Get the filepath and filename from server temp dir
$sourceFile   = $_FILES[ 'Filedata' ][ 'tmp_name' ]; // e.g. c:\server\path\tmp\php159.tmp

// Solution 1 for getting file extension
$fileExt1     = pathinfo($sourceFile, PATHINFO_EXTENSION); // <-- This only returns .tmp

// Solution 2 with getimagesize
list(,,$extension) = getimagesize($sourceFile);
$fileExt2     = $extension; // this only returns the number 2.

// Solution 3 with getimagesize
$img = getimagesize($sourceFile);
$fileExt3 = $img[2]; // this only returns the number 2.

我不使用正则表达式读取文件名，因为用户可以给文件命名任何东西，所以我必须读取文件数据.

I'm not using regex to read filename, because a user may name the file anything, so I have to read file data.

有人建议吗?

推荐答案

好吧，首先$ sourceFile应该是$_FILES['Filedata']['name']而不是$_FILES['Filedata']['tmp_name']，但是仅用于第一个解决方案.

Well, first off $sourceFile should be $_FILES['Filedata']['name'] instead of $_FILES['Filedata']['tmp_name'] but only for your first solution.

现在有关您的解决方案/问题:

Now regarding your solutions/problems:

1. pathinfo($sourceFile, PATHINFO_EXTENSION);//应该可以正常工作
2. getimagesize()返回一个常量，该常量指示第二个索引中的图像类型
3. 与第2点相同

1. pathinfo($sourceFile, PATHINFO_EXTENSION); // should work now
2. getimagesize() returns a constant indicating the image type in the second index
3. same as point 2

请记住，exif_imagetype()返回的信息与getimagesize()的第二个索引完全相同，如果可以使用此功能，它的性能应该会更好.

Keep in mind that exif_imagetype() returns exactly the same information as the second index of getimagesize(), if you have access to this function it should perform way better.

现在，对于图像常量，最常见的三个是:

Now for the image constants, the most common three are:

• IMAGETYPE_GIF = 1
• IMAGETYPE_JPEG = 2
• IMAGETYPE_PNG = 3

检查就像做这样的事情一样简单:

Checking is as simple as doing something like this:

switch (exif_imagetype($_FILES['Filedata']['tmp_name']))
{
    case IMAGETYPE_GIF:
        echo 'is a GIF';
    break;

    case IMAGETYPE_JPEG:
        echo 'is a JPEG';
    break;

    case IMAGETYPE_PNG:
        echo 'is a PNG';
    break;

    case default:
        echo 'is something else;
    break;
}

还有一件事，使用getimagesize()/exif_imagetype()比依靠文件扩展名更好，因为扩展名可以轻松更改.

One more thing, it's better to use getimagesize() / exif_imagetype() than to rely on the file extension, since the extension can be easily changed.

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