php限制上传文件类型并保存上传文件

下面的代码演示了php中如何获取用户上传的文件，并限制文件类型的一般图片文件，最后保存到服务器

1. $allowedExts = array("gif", "jpeg", "jpg", "png");
2. $extension = end(explode(".", $_FILES["file"]["name"]));
3. if ((($_FILES["file"]["type"] == "image/gif")
4. || ($_FILES["file"]["type"] == "image/jpeg")
5. || ($_FILES["file"]["type"] == "image/jpg")
6. || ($_FILES["file"]["type"] == "image/pjpeg")
7. || ($_FILES["file"]["type"] == "image/x-png")
8. || ($_FILES["file"]["type"] == "image/png"))
9. && ($_FILES["file"]["size"] < 20000)
10. && in_array($extension, $allowedExts))
11. {
12. if ($_FILES["file"]["error"] > 0)
13. {
14. echo "Return Code: " . $_FILES["file"]["error"] . "
    ";
15. }
16. else
17. {
18. echo "Upload: " . $_FILES["file"]["name"] . "
    ";
19. echo "Type: " . $_FILES["file"]["type"] . "
    ";
20. echo "Size: " . ($_FILES["file"]["size"] / 1024) . " kB
    ";
21. echo "Temp file: " . $_FILES["file"]["tmp_name"] . "
    ";
23. if (file_exists("upload/" . $_FILES["file"]["name"]))
24. {
25. echo $_FILES["file"]["name"] . " already exists. ";
26. }
27. else
28. {
29. move_uploaded_file($_FILES["file"]["tmp_name"],
30. "upload/" . $_FILES["file"]["name"]);
31. echo "Stored in: " . "upload/" . $_FILES["file"]["name"];
32. }
33. }
34. }
35. else
36. {
37. echo "Invalid file";
38. }
39. ?>