PHP File Upload principle of simple introduction

PHP File Upload principle simple analysis, learning PHP friends can refer to, indeed more than the ASP is much simpler.

Form uploads can only be used in MULTIPART/FORM-DATA encoded format
$_files system functions;
$_files[' myFile ' [' name '] file name
$_files[' myFile ' [' type '] file types, limited by server
image/**
Image/x-png
Application/x-zip-compressed
$_files[' myFile ' [' Size '] upload file size
$_files[' myFile ' [' tmp_name '] save temporary file name after uploading service
$_files[' myFile ' [' ERROR '] error code;
0 Success 1 exceeds php.ini size 2 value specified by Max_file_size option
3 only partially uploaded 5 upload file size is 0

Move_uploaded_file (temporary file, target location and file name);
Functions for moving files to the target location after uploading
Is_uploaded_file (MIME);
To determine the file function of the upload MIME type

The code is as follows:

<form enctyoe= "Multipart/form-data" method= "post" name= "Upload" > < Input name= "upfile" name= "name" > </form> if (is_uploaded_file ($_files[' myFile ' [' tmp_name '])) {$upfile = $_ files[' upload '; $name = $upfile [' name ']; $type = $upfile [' type ']; $size = $upfile [' Size ']; $tmp _name = $upfile [' Tmp_name ']; $error = $upfile [' ERROR ']; Switch ($type) {case ' image/pjpeg ': $ok =1; break} if ($ok) {move_uploaded_file ($tmp _name, ' up/'. $name);} else{echo "File type not allowed";}}