If PHP returns messages saying that functions have depreciated, this is a warning to indicate that the code that you are running has functions in your installed version of PHP that will be removed at some time in the future by a later version of PHP.

This may occur if one day your web host suddenly decides to upgrade their servers to a new version of PHP.  You should make sure that you are on the mailing lists for your hosting company so that you will be notified of changes that may cause issues.

Depreciated functions still exist and you get warnings. So they work as expected.  However in a future version of PHP, they might disappear.  It’s a way to signal changes to users which have code based on an older PHP version.

Normally the deprecated features get removed after some time, but it’s not predictable how long this takes.

So if you see these warnings, update the code. Most often the PHP documentation has more information why something has been deprecated and what to do. Most often it’s an improvement.

Changing to a new version of PHP will mean that you will have access to the latest features of the language, however, it may mean that older versions of an application will either fail or display warning messages.

You have to decide if you want your application to operate over different PHP platforms – if you do then you have to code with common functions that are in all versions of PHP.

PHP File handling Tutorial

The kinds of things that you will do with files include:

•    Reading and writing text in files.
•    Creating and deleting directories and file manipulation.

Part 1 – File permissions on the server

If you have to write data to a text file on a web server, or you have to copy, rename, delete or do any kind of file manipulation, the file or folder will require correct permissions.

To change file or folder permissions in Dreamweaver, open the site up in the remote view and right click on the file or folder.  Select permissions and then choose the kind of permissions that you want.  This would be 666 if you want to write and manipulate files.

This may not be necessary, as it may already be set on your web server.

Part 2 – Working with files

The typical way in which you will work with a text file is something like:

•    Open the file that you are going to work with by associating a file handle
•    Read or write to the file using the file handle
•    Close the file using the file handle.

Task 1 – Opening a file

(1)   In your text editor create a new PHP web page called file.php.  If you are using Dreamweaver, remove all the html code from the page.

(2)  Enter the following:

<?php

//file.php
$filename = “data.txt”;

if  (  !$fp = fopen($filename, “r”) )
{
die (“cannot open file $filename”);
}

fclose($fp);

?>

The $fp is the file pointer which is used for reading and writing operations.

(3)  Upload the file to your web space and run it in your web browser and see what happens.

(4)   Create a text file called data.txt and upload it to the web space and run file.php in your browser again.

The fopen() function

fopen() takes two arguments.  The first argument is the file name.  The file name can be relative to the location of this PHP file, or absolute with the full path name of the file in the form “/myfiles/www/data.txt” or it can be a url or an ftp path name to a different server.

The second argument is the mode which can be:

r   Read only access
r+ Read and write access
w Write access only
w+ Read and write access, any existing data will be lost if the file does not exit and PHP will attempt to create the file
a Appending only.  Write to the end of the file, if the file does not exist then PHP will attempt to create the file
a+ Open for reading and appending. Data is written to the end of the file, if the file does not exist, then PHP will attempt to create it.

Task 2 – Writing to the file

(1)  In file.php, change the mode from r to w+

(2)  Before the fclose() line enter the following:

(3)  fwrite($fp, “this is some text);

(4)  Your file will now look like:

<?php

//file.php

$filename = “data.txt”;

if  (  !$fp = fopen($filename, “w+”) )
{
die (“cannot open file $data.txt”);
}

fwrite($fp, “this is some text”);

fclose($fp);

?>

(5)  Upload the file to your web server, and run file.php in your web browser.  When you examine the data.txt file you should see the extra text.

Task 3 – Reading from the file

There are a number of ways of reading the contents of file.  One method is to read a block of characters into an array until the end of the file is reached

while ( !feof($fp) ) {
$lines[] = fgets($fp, 1024);
}

fgets($fp, 1024) means to read a line with up to 1024 bytes or until an end of line is found.

(1) Modify file.php with the above code added and an extra bit of code to display the text in the array.

The file.php code will now look like:

<?php

//file.php

$filename = “data.txt”;

if  (  !$fp = fopen(“data.txt”, “w+”) )
{
die (“cannot open file $data.txt”);
}

fwrite($fp, “this is some text\r\n”);
fwrite($fp, “this is some more text\r\n”);
fwrite($fp, “this is even more text\r\n”);

while ( !feof($fp) ) {
$lines[] = fgets($fp, 1024);
}

fclose($fp);

foreach ($lines as $key => $value) {
echo($value . “<br/>”);
}
?>

(2) Upload the file to the web server and run it in your web browser.  It should display the text that has been entered into the file.
Part 3 – File and folder manipulation

There are a number of PHP functions that can be used to work with files and folders.

Some of these functions may need permissions to be modified on the server to allow.

copy() copy a file
rename() rename a file
file_exists() shows if the file exists
basename() returns the base part of a file name

In PHP6, get_magic_qu0tes_gpc will be depreciated, but you may still want to be able to test for it if you do not know which version of PHP it will be running on.

Here are two possible ways of how this might be done.  Both of these create a new function called is_get_magic_quotes_gpc to make it easier to search and replace in a number of files.

First method :

<?php

/**
Returns true if have to make allowances for magic quotes or not
Returns true if magic quotes are on false otherwise
Test which version of PHP you have and make allowences as appropriate
**/
function is_get_magic_quotes_gpc() {

if ( version_compare(phpversion(), ‘6’, ‘<‘) ) {

if ( get_magic_quotes_gpc() ) {
return true;
}
else
{
return false;
}

}
else
{
return false;
}

}
?>

Second method :

<?php

/**
Returns true if have to make allowances for magic quotes or not
Returns true if magic quotes are on false otherwise
Test if the function exists or not and then make allowances as appropriate
**/
function is_get_magic_quotes_gpc() {

if ( function_exists(“get_magic_quotes_gpc”) )
{
if ( get_magic_quotes_gpc() ) {
return true;
}
else
{
return false;
}
}
else
{
return false;
}

}

?>

Both of these can be tested using :

<?php

if ( is_get_magic_quotes_gpc() ) {
echo(“yes”);
}
else
{
echo(“no”);
}

echo(“<p>php version : ” . phpversion() . “</p>”);

?>

When you do an insert SQL statement which creates a new record, you often want to return the value of the auto-incremented field.

You can do this in PHP by:

$recid = mysql_insert_id(); //Return the number of the automatically incremented field after the insert statement

this is done after your mysql_query($sqlquery); statement