科技回声

To all PHP hackers out there, I have a basic PHP question. The application I am working on currently allows a user to upload a jpeg or gif image only. My code for enforcing this rule is as follows:if($type!="image/gif" || $type!="image/jpeg"){ $error = "Your image needs to have a gif or jpeg format"; }$type in this case is obtained from $_FILES['file']['type']However, this does not seem to work. Non-JPEG images get rejected properly. However even JPEG images are rejected. Any ideas on how I can check the type of the image.

Ummm, that statement is always going to be true. This isn't a PHP question this is a basic logic question.You really want...if (!(type == gif or type == jpeg)) { error }or change your 'or' to an 'and' ie:if (type!=gif and type!=jpeg) { error }<a href="http://en.wikipedia.org/wiki/De_Morgan's_laws" rel="nofollow">http://en.wikipedia.org/wiki/De_Morgan's_laws</a>

consider using the getimagesize function. <a href="http://us.php.net/getimagesize" rel="nofollow">http://us.php.net/getimagesize</a> the comments have some useful info on how to get the image type.iirc, the problem using the file type string is that its not consistent.

An easy way to debug is to just echo $type for a file that you want to allow and see what it is :)

try: ($type!="image/gif" || $type!="image/jpeg" || $type!="image/jpg" || $type!="image/prjpeg")

An easy way to debug is to just echo $type for a file that you want to allow and see what it is :)

try: ($type!="image/gif" || $type!="image/jpeg" || $type!="image/jpg" || $type!="image/prjpeg")

PHP coding question

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PHP coding question

4 条评论