How to Upload a file using PHP

Question

I am new to PHP. The following code should display "OK" once a file is selected from the Upload Dialog Box. But to my surprise there is no output on the screen. Please Help!!!

  <?php
       if(isset($_FILES['file']['name']))
               $name = $_FILES['file']['name'];

       if(isset($_FILES['file']['tmp_name']))
               $tmp_name = $_FILES['file']['tmp_name'];

       if(isset($name))
       {
              if(!empty($name))
                  echo 'OK';
              else
                  echo 'Please chose a file';
       }

  ?>

   <form action="up.php" method="POST" encrypt="multipart/form-data">
          <input type="file" name="file"><br><br>
          <input type="submit" value="Submit">
   </form>

The "once a file is selected" suggests you expect it to appear immediately? The `$_FILES` superglobal is only set *after* the upload is done. PHP is a server side language and cannot monitor a file input. You'll need a Javascript based solution for that. — Oldskool, Dec 13 '14 at 11:45
possible duplicate of [What is the difference between client-side and server-side programming?](http://stackoverflow.com/questions/13840429/what-is-the-difference-between-client-side-and-server-side-programming) — Artjom B., Dec 13 '14 at 11:47
Once the image is uploaded, the page refreshes and as it is a PHP(server side script) it will not be able to display the echo "OK";. You will need to use AJAX to run your PHP function and echo out your OK or error message... — user3806613, Dec 13 '14 at 11:50

score 1 · Answer 1 · edited Jun 30 '15 at 15:21

With PHP, it is easy to upload files to the server. I have tried to cover all things and make it as simple as possible.

In your "php.ini" file, search for the file_uploads directive, and set it to On:

file_uploads = On

You may also need to change the allowed file sizes in the php.ini file if the file you are trying to upload is bigger than what is allowed:

post_max_size = 8M; //make larger if needed
upload_max_filesize = 8M; //make larger if needed

After making these changes make sure to restart your webserver (apache/nginx.)

upload_max_filesize should never be bigger than post_max_size

Create an HTML form that allow users to choose the image file they want to upload:

<!DOCTYPE html>
<html>
<body>

<form action="upload.php" method="post" enctype="multipart/form-data">
    Select image to upload:
    <input type="file" name="fileToUpload" id="fileToUpload">
    <input type="submit" value="Upload Image" name="submit">
</form>

</body>
</html>

Some rules to follow for the HTML form above:

Make sure that the form uses method="post"
The form also needs the following attribute: enctype="multipart/form-data". It specifies which content-type to use when submitting the form

Without the requirements above, the file upload will not work.

Other things to notice:

The type="file" attribute of the tag shows the input field as a file-select control, with a "Browse" button next to the input control

The form above sends data to a file called "upload.php", which we will create next.

The "upload.php" file contains the code for uploading a file:

<?php
$target_dir = "uploads/";
$target_file = $target_dir . basename($_FILES["fileToUpload"]["name"]);
$uploadOk = 1;
$imageFileType = pathinfo($target_file,PATHINFO_EXTENSION);
// Check if image file is a actual image or fake image
if(isset($_POST["submit"])) {
    $check = getimagesize($_FILES["fileToUpload"]["tmp_name"]);
    if($check !== false) {
        echo "File is an image - " . $check["mime"] . ".";
        $uploadOk = 1;
    } else {
        echo "File is not an image.";
        $uploadOk = 0;
    }
}
// Check if file already exists
if (file_exists($target_file)) {
    echo "Sorry, file already exists.";
    $uploadOk = 0;
}
// Check file size
if ($_FILES["fileToUpload"]["size"] > 500000) {
    echo "Sorry, your file is too large.";
    $uploadOk = 0;
}
// Allow certain file formats
if($imageFileType != "jpg" && $imageFileType != "png" && $imageFileType != "jpeg"
&& $imageFileType != "gif" ) {
    echo "Sorry, only JPG, JPEG, PNG & GIF files are allowed.";
    $uploadOk = 0;
}
// Check if $uploadOk is set to 0 by an error
if ($uploadOk == 0) {
    echo "Sorry, your file was not uploaded.";
// if everything is ok, try to upload file
} else {
    if (move_uploaded_file($_FILES["fileToUpload"]["tmp_name"], $target_file)) {
        echo "The file ". basename( $_FILES["fileToUpload"]["name"]). " has been uploaded.";
    } else {
        echo "Sorry, there was an error uploading your file.";
    }
}
?>

Some variables explanations:

$target_dir = "uploads/" - specifies the directory where the file is going to be placed
$target_file specifies the path of the file to be uploaded
$uploadOk=1 is used as a flag
$imageFileType holds the file extension of the file

How to Upload a file using PHP

1 Answers1