PHP File
Uploading
A PHP script can be used with a HTML form to allow
users to upload files to the server. Initially files are uploaded into a
temporary directory and then relocated to a target destination by a PHP script.
Information in the phpinfo.php page
describes the temporary directory that is used for file uploads as upload_tmp_dir and the maximum permitted size
of files that can be uploaded is stated as upload_max_filesize.
These parameters are set into PHP configuration file php.ini
The process of uploading a file follows these steps
−
·
The user opens the page containing a
HTML form featuring a text files, a browse button and a submit button.
·
The user clicks the browse button and
selects a file to upload from the local PC.
·
The full path to the selected file
appears in the text filed then the user clicks the submit button.
·
The selected file is sent to the
temporary directory on the server.
·
The PHP script that was specified as
the form handler in the form's action attribute checks that the file has
arrived and then copies the file into an intended directory.
·
The PHP script confirms the success to
the user.
As usual when writing files it is necessary for
both temporary and final locations to have permissions set that enable file
writing. If either is set to be read-only then process will fail.
An uploaded file could be a text file or image file
or any document.
Creating an
upload form
The following HTM code below creates an uploader form. This form is having method attribute set to post and
enctype attribute is set to multipart/form-data
<?php
if(isset($_FILES['image'])){
$errors= array();
$file_name = $_FILES['image']['name'];
$file_size =$_FILES['image']['size'];
$file_tmp =$_FILES['image']['tmp_name'];
$file_type=$_FILES['image']['type'];
$file_ext=strtolower(end(explode('.',$_FILES['image']['name'])));
$expensions= array("jpeg","jpg","png");
if(in_array($file_ext,$expensions)=== false){
$errors[]="extension not allowed, please choose a JPEG or PNG file.";
}
if($file_size > 2097152){
$errors[]='File size must be excately 2 MB';
}
if(empty($errors)==true){
move_uploaded_file($file_tmp,"images/".$file_name);
echo "Success";
}else{
print_r($errors);
}
}
?>
<html>
<body>
<form action="" method="POST" enctype="multipart/form-data">
<input type="file" name="image" />
<input type="submit"/>
</form>
</body>
</html>
It will produce the following result −
Creating an
upload script
There is one global PHP variable called $_FILES.
This variable is an associate double dimension array and keeps all the
information related to uploaded file. So if the value assigned to the input's
name attribute in uploading form wasfile, then
PHP would create following five variables −
·
$_FILES['file']['tmp_name'] − the uploaded file in the temporary
directory on the web server.
·
$_FILES['file']['name'] −
the actual name of the uploaded file.
·
$_FILES['file']['size'] −
the size in bytes of the uploaded file.
·
$_FILES['file']['type'] −
the MIME type of the uploaded file.
·
$_FILES['file']['error'] −
the error code associated with this file upload.
Example
Below example should allow upload images and gives
back result as uploaded file information.
<?php
if(isset($_FILES['image'])){
$errors= array();
$file_name = $_FILES['image']['name'];
$file_size = $_FILES['image']['size'];
$file_tmp = $_FILES['image']['tmp_name'];
$file_type = $_FILES['image']['type'];
$file_ext=strtolower(end(explode('.',$_FILES['image']['name'])));
$expensions= array("jpeg","jpg","png");
if(in_array($file_ext,$expensions)=== false){
$errors[]="extension not allowed, please choose a JPEG or PNG file.";
}
if($file_size > 2097152) {
$errors[]='File size must be excately 2 MB';
}
if(empty($errors)==true) {
move_uploaded_file($file_tmp,"images/".$file_name);
echo "Success";
}else{
print_r($errors);
}
}
?>
<html>
<body>
<form action = "" method = "POST" enctype = "multipart/form-data">
<input type = "file" name = "image" />
<input type = "submit"/>
<ul>
<li>Sent file: <?php echo $_FILES['image']['name']; ?>
<li>File size: <?php echo $_FILES['image']['size']; ?>
<li>File type: <?php echo $_FILES['image']['type'] ?>
</ul>
</form>
</body>
</html>
It will produce the following result −
Array ( [0]
=> extension not allowed, please choose a JPEG or PNG file. )
Upload or Browse Box Here