File And Directory Manipulation In PHP (part 2) - Beam Me Up (Page 7 of 13 )
Most often, you'll find yourself using rename(), copy() and unlink() functions in the context of files uploaded to PHP via a Web browser - so-called "HTTP file uploads". Consider the following example, which
demonstrates:
<html>
<head>
</head>
<body>
<?php
if (!$_POST['submit'])
{
?>
<form enctype="multipart/form-data" action="<?=$_SERVER['PHP_SELF']?>"
method="post">
Description:
<br>
<input type="Text" name="desc" size="40">
<p>
File:
<br>
<input type="file" name="file">
<p>
<input type="submit" name="submit" value="Add Image">
</form>
<?
}
else
{
// validate form data
if ($_FILES['file']['size'] == 0) { die("Bad upload!"); }
if ($_FILES['file']['type'] != "image/gif" && $_FILES['file']['type']
!= "image/jpeg" && $_FILES['file']['type'] !=
"image/pjpeg") { die("Invalid file format!"); }
if (!$_POST['desc']) { die("No description!"); }
// open connection to database
$connection = mysql_connect("localhost", "root", "secret")
or die ("Unable to connect!");
mysql_select_db("db1") or die ("Unable to select database!");
// formulate and execute query
$query = "INSERT INTO gallery (dsc) VALUES ('" . $_POST['desc']. "')";
$result = mysql_query($query) or die("Error in query: " . mysql_error());
$id = mysql_insert_id($connection);
// get file type and rename file to recordID.ext
if ($_FILES['file']['type'] == "image/gif") { $ext = ".gif";
}
if ($_FILES['file']['type'] == "image/jpeg") { $ext = ".jpg";
}
if ($_FILES['file']['type'] == "image/pjpeg") { $ext = ".jpg";
}
$newFileName = $id . $ext;
// copy file to new location
copy($_FILES['file']['tmp_name'], "/mydatadir/" . $newFileName);
// update database with new file name
$query = "UPDATE gallery SET filename = '$newFileName' WHERE id = '$id'";
$result = mysql_query($query) or die("Error in query: " . mysql_error());
}
?>
</body>
</html>
In this case, when a file is uploaded, it is automatically stored in a temporary directory by PHP, and its temporary filename is exposed via the "tmp_name" key of the $_FILES array. A copy() function can then be used to copy the uploaded file from its temporary location to its new location, and it can also be renamed along the way if needed (as in the above example). Once the script finishes executing, the temporary file is automatically deleted by PHP.
Since file uploads are fairly common in PHP, the language also offers two specialized functions designed specifically to assist you in the process of handling such uploaded files: the is_uploaded_file() function, which tests if a file was uploaded via the HTTP POST method, and the
move_uploaded_file() function, which is used to move an uploaded file to a new location after verifying its integrity. Here is a rewrite of the previous example using these functions, in order to better illustrate how they can be used:
<html>
<head>
</head>
<body>
<?php
if (!$_POST['submit'])
{
?>
<form enctype="multipart/form-data" action="<?=$_SERVER['PHP_SELF']?>"
method="post">
Description:
<br>
<input type="Text" name="desc" size="40">
<p>
File:
<br>
<input type="file" name="file">
<p>
<input type="submit" name="submit" value="Add Image">
</form>
<?
}
else
{
// validate form data
if ($_FILES['file']['size'] == 0) { die("Bad upload!"); }
if ($_FILES['file']['type'] != "image/gif" && $_FILES['file']['type']
!= "image/jpeg" && $_FILES['file']['type'] !=
"image/pjpeg") { die("Invalid file format!"); }
if (!$_POST['desc']) { die("No description!"); }
if (!is_uploaded_file($_FILES['file']['tmp_name'])) { die("Bad file!");
}
// open connection to database
$connection = mysql_connect("localhost", "root", "secret")
or die ("Unable to connect!");
mysql_select_db("db1") or die ("Unable to select database!");
// formulate and execute query
$query = "INSERT INTO gallery (dsc) VALUES ('" . $_POST['desc']. "')";
$result = mysql_query($query) or die("Error in query: " . mysql_error());
$id = mysql_insert_id($connection);
// get file type and rename file to recordID.ext
if ($_FILES['file']['type'] == "image/gif") { $ext = ".gif";
}
if ($_FILES['file']['type'] == "image/jpeg") { $ext = ".jpg";
}
if ($_FILES['file']['type'] == "image/pjpeg") { $ext = ".jpg";
}
$newFileName = $id . $ext;
// move file to new location
move_uploaded_file($_FILES['file']['tmp_name'], "/mydatadir/" .
$newFileName) or die("Could not move file!");
// update database with new file name
$query = "UPDATE gallery SET filename = '$newFileName' WHERE id = '$id'";
$result = mysql_query($query) or die("Error in query: " . mysql_error());
}
?>
</body>
</html>
Next: Diving Into Directories >>
More PHP Articles
More By icarus, (c) Melonfire
/ 59 
