PHP Date
<?php
echo date("Y/m/d") . "<br />"; output:2012/08/07
echo date("Y.m.d") . "<br />"; 2012.08.07
echo date("Y-m-d"); 2012-08-07
?>
Syntax for mktime():
mktime(hour,minute,second,month,day,year,is_dst)
example:
<?php
$tomorrow = mktime(0,0,0,date("m"),date("d")+1,date("Y"));
echo "Tomorrow is ".date("Y/m/d", $tomorrow);
?>
output: Tomorrow is 2012/08/07
PHP Include
<?php include 'header.php';
echo '<a href="/default.php">Home</a>
<a href="/tutorials.php">Tutorials</a>
<a href="/references.php">References</a>
<a href="/examples.php">Examples</a>
<a href="/about.php">About Us</a>
<a href="/contact.php">Contact Us</a>';
?>
PHP File Upload
index.php
<html>
<body>
<form action="upload_file.php" method="post"
enctype="multipart/form-data">
<label for="file">Filename:</label>
<input type="file" name="file" id="file" />
<br />
<input type="submit" name="submit" value="Submit" />
</form>
</body>
</html>
upload_file.php
<?php
if ($_FILES["file"]["error"] > 0)
{
echo "Error: " . $_FILES["file"]["error"] . "<br />";
}
else
{
echo "Upload: " . $_FILES["file"]["name"] . "<br />";
echo "Type: " . $_FILES["file"]["type"] . "<br />";
echo "Size: " . ($_FILES["file"]["size"] / 1024) . " Kb<br />";
echo "Stored in: " . $_FILES["file"]["tmp_name"];
}
?>
By using the global PHP $_FILES array you can upload files from a client computer to the remote server.
The first parameter is the form's input name and the second index can be either "name", "type", "size", "tmp_name" or "error". Like this:
- $_FILES["file"]["name"] - the name of the uploaded file
- $_FILES["file"]["type"] - the type of the uploaded file
- $_FILES["file"]["size"] - the size in bytes of the uploaded file
- $_FILES["file"]["tmp_name"] - the name of the temporary copy of the file stored on the server
- $_FILES["file"]["error"] - the error code resulting from the file upload
This is a very simple way of uploading files. For security reasons, you should add restrictions on what the user is allowed to upload.
Saving and Restriction File Upload:
<?php
$allowedExts = array("jpg", "jpeg", "gif", "png");
$extension = end(explode(".", $_FILES["file"]["name"]));
if ((($_FILES["file"]["type"] == "image/gif")
|| ($_FILES["file"]["type"] == "image/jpeg")
|| ($_FILES["file"]["type"] == "image/pjpeg"))
&& ($_FILES["file"]["size"] < 20000)
&& in_array($extension, $allowedExts))
{
if ($_FILES["file"]["error"] > 0)
{
echo "Return Code: " . $_FILES["file"]["error"] . "<br />";
}
else
{
echo "Upload: " . $_FILES["file"]["name"] . "<br />";
echo "Type: " . $_FILES["file"]["type"] . "<br />";
echo "Size: " . ($_FILES["file"]["size"] / 1024) . " Kb<br />";
echo "Temp file: " . $_FILES["file"]["tmp_name"] . "<br />";
if (file_exists("upload/" . $_FILES["file"]["name"]))
{
echo $_FILES["file"]["name"] . " already exists. ";
}
else
{
move_uploaded_file($_FILES["file"]["tmp_name"],
"upload/" . $_FILES["file"]["name"]);
echo "Stored in: " . "upload/" . $_FILES["file"]["name"];
}
}
}
else
{
echo "Invalid file";
}
?>
PHP Sessions
Starting and Storing Session Variables
<?php
session_start();
// store session data
$_SESSION['views']=1;
?>
<html>
<body>
<?php
//retrieve session data
echo "Pageviews=". $_SESSION['views'];
?>
</body>
</html>
Destroying Session:
If you wish to delete some session data, you can use the unset() or the session_destroy() function.
The unset() function is used to free the specified session variable:
<?php
session_start();
if(isset($_SESSION['views']))
unset($_SESSION['views']);
?>
session_start();
if(isset($_SESSION['views']))
unset($_SESSION['views']);
?>
You can also completely destroy the session by calling the session_destroy() function:
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