PHP file Upload settings and processing (single file)

<!--upload.php Content--
<?php
/*
Modify the settings for PHP.ini
File_uploads must be on
Upload_max_filesize set the size of the upload file, which is less than post_max_size
Post_max_size set the maximum value that the Post method can receive
Upload_tmp_dir temporary directory where uploaded files are stored
*/
Header ("Content-type:text/html;charset=utf-8");
/*
Array
(
[pic] = Array
(
[Name] = 195_4074_831a070561e20a0.jpg
[Type] = Image/jpeg
[Tmp_name] = C:\wamp\tmp\php45.tmp
[ERROR] = 0
[Size] = 43274
)
)
*/
First step: Judging errors
if ($_files[' pic ' [' ERROR '] > 0) {
Switch ($_files[' pic ' [' ERROR ']) {
Case 1:
echo "indicates that the size of the uploaded file exceeds the agreed value. The maximum size of the file is specified in the PHP configuration file, and the instruction is:upload_max_filesize<br> ";
Break
Case 2:
echo "indicates that the upload file size exceeds the maximum value specified by the Max_file_size element of the HTML form's hidden field property 1m<br>";
Break
Case 3:
echo "indicates that the file is only partially uploaded <br>";
Break
Case 4:
echo "means not uploading any files <br>";
Break

Default
echo "Last known error <br>";
Break
}
Exit
}

Step two: Determine the type
$arr = Explode (".", basename ($_files[' pic ' [' name ']));
$hz = Array_pop ($arr);

$allowtype =array ("gif", "png", "JPG", "jpeg");

if (!in_array ($hz, $allowtype)) {
echo "The type of upload is not legal";
Exit
}

Step three: Determine the size
$maxsize = 1000000;
if ($_files[' pic ' [' size '] > $maxsize) {
echo "uploaded file exceeded, {$maxsize} bytes!";
Exit
}

The fourth step, the file name after uploading must be set
$tmpfile = $_files[' pic ' [' tmp_name '];
Set Random file names
$srcname = "./uploads/". Date ("Ymdhis"). Rand (100, 999). ".". $hz;

Copy the uploaded file under the temporary directory to the directory I specified, and the specified name can be uploaded.
if (Move_uploaded_file ($tmpfile, $srcname)) {
echo "Upload succeeded!";
}else{
echo "Upload failed!";
}
?>

<!--upform.html Content--
<!--upload a form, you must use the Post method, enctype= "Multipart/form-data" must be used--
<form action= "upload.php" method= "post" enctype= "Multipart/form-data" >
Name: <input type= "text" name= "username" value= "/><br>
<!--hide the form, the effect is to be prompted when the file exceeds 1m, just a friendly hint--
<input type= "hidden" name= "max_file_size" value= "1000000"/>
Up Pic: <input type= "file" name= "pic" value= "" ><br>

<input type= "Submit" value= "Upload"/><br>

</form>

PHP file Upload settings and processing (single file)