Detaillierte Einführung in 36 Strategien zur Verbesserung der PHP-Codequalität

require_once('../../lib/some_class.php');

define('ROOT' , '/var/www/project/');
require_once(ROOT . '../../lib/some_class.php');

//rest of the code

//suppose your script is /var/www/project/index.php
//Then __FILE__ will always have that full path.

define('ROOT' , pathinfo(__FILE__, PATHINFO_DIRNAME));
require_once(ROOT . '../../lib/some_class.php');

//rest of the code

require_once('lib/Database.php');
require_once('lib/Mail.php');

require_once('helpers/utitlity_functions.php');

function load_class($class_name)
{
    //path to the class file
    $path = ROOT . '/lib/' . $class_name . '.php');
    require_once( $path );
}

load_class('Database');
load_class('Mail');

function load_class($class_name)
{
    //path to the class file
    $path = ROOT . '/lib/' . $class_name . '.php');

    if(file_exists($path))
    {
        require_once( $path );
    }
}

define('ENVIRONMENT' , 'development');

if(! $db->query( $query )
{
    if(ENVIRONMENT == 'development')
    {
        echo "$query failed";
    }
    else
    {
        echo "Database error. Please contact administrator";
    }
}

define('ENVIRONMENT' , 'production');

if(! $db->query( $query )
{
    if(ENVIRONMENT == 'development')
    {
        echo "$query failed";
    }
    else
    {
        echo "Database error. Please contact administrator";
    }
}

/**
	Method to execute a command in the terminal
	Uses :

	1. system
	2. passthru
	3. exec
	4. shell_exec

*/
function terminal($command)
{
	//system
	if(function_exists('system'))
	{
		ob_start();
		system($command , $return_var);
		$output = ob_get_contents();
		ob_end_clean();
	}
	//passthru
	else if(function_exists('passthru'))
	{
		ob_start();
		passthru($command , $return_var);
		$output = ob_get_contents();
		ob_end_clean();
	}

	//exec
	else if(function_exists('exec'))
	{
		exec($command , $output , $return_var);
		$output = implode("\n" , $output);
	}

	//shell_exec
	else if(function_exists('shell_exec'))
	{
		$output = shell_exec($command) ;
	}

	else
	{
		$output = 'Command execution not possible on this system';
		$return_var = 1;
	}

	return array('output' => $output , 'status' => $return_var);
}

terminal('ls');

function add_to_cart($item_id , $qty)
{
    $_SESSION['cart']['item_id'] = $qty;
}

add_to_cart( 'IPHONE3' , 2 );

function add_to_cart($item_id , $qty)
{
    if(!is_array($item_id))
    {
        $_SESSION['cart']['item_id'] = $qty;
    }

    else
    {
        foreach($item_id as $i_id => $qty)
        {
            $_SESSION['cart']['i_id'] = $qty;
        }
    }
}

add_to_cart( 'IPHONE3' , 2 );
add_to_cart( array('IPHONE3' => 2 , 'IPAD' => 5) );

<?php

echo "Hello";

//Now dont close this tag

<?php
class super_class
{
    function super_function()
    {
        //super code
    }
}
?>
//super extra character after the closing tag

require_once('super_class.php');

//echo an image or pdf , or set the cookies or session data

<?php
class super_class
{
    function super_function()
    {
        //super code
    }
}

//No closing tag

function print_header()
{
    echo "<p id=&#39;header&#39;>Site Log and Login links</p>";
}

function print_footer()
{
    echo "<p id=&#39;footer&#39;>Site was made by me</p>";
}

print_header();
for($i = 0 ; $i < 100; $i++)
{
    echo "I is : $i <br />&#39;;
}
print_footer();

function print_header()
{
    $o = "<p id=&#39;header&#39;>Site Log and Login links</p>";
    return $o;
}

function print_footer()
{
    $o = "<p id=&#39;footer&#39;>Site was made by me</p>";
    return $o;
}

echo print_header();
for($i = 0 ; $i < 100; $i++)
{
    echo "I is : $i <br />&#39;;
}
echo print_footer();

$xml = &#39;<?xml version="1.0" encoding="utf-8" standalone="yes"?>&#39;;
$xml = "<response>
  <code>0</code>
</response>";

//Send xml data
echo $xml;

$xml = &#39;<?xml version="1.0" encoding="utf-8" standalone="yes"?>&#39;;
$xml = "<response>
  <code>0</code>
</response>";

//Send xml data
header("content-type: text/xml");
echo $xml;

header("content-type: application/x-javascript");
echo "var a = 10";

//Attempt to connect to database
$c = mysqli_connect($this->host , $this->username, $this->password);

//Check connection validity
if (!$c) 
{
	die ("Could not connect to the database host: <br />". mysqli_connect_error());
}

//Set the character set of the connection
if(!mysqli_set_charset ( $c , &#39;UTF8&#39; ))
{
	die(&#39;mysqli_set_charset() failed&#39;);
}

$value = htmlentities($this->value , ENT_QUOTES , CHARSET);

$images = array(
 'myself.png' , 'friends.png' , 'colleagues.png'
);

$js_code = '';

foreach($images as $image)
{
$js_code .= "'$image' ,";
}

$js_code = 'var images = [' . $js_code . ']; ';

echo $js_code;

//Output is var images = ['myself.png' ,'friends.png' ,'colleagues.png' ,];

$images = array(
 'myself.png' , 'friends.png' , 'colleagues.png'
);

$js_code = 'var images = ' . json_encode($images);

echo $js_code;

//Output is : var images = ["myself.png","friends.png","colleagues.png"]

$contents = "All the content";
$file_path = "/var/www/project/content.txt";

file_put_contents($file_path , $contents);

$contents = "All the content";
$dir = '/var/www/project';
$file_path = $dir . "/content.txt";

if(is_writable($dir))
{
    file_put_contents($file_path , $contents);
}
else
{
    die("Directory $dir is not writable, or does not exist. Please check");
}

// Read and write for owner, read for everybody else
chmod("/somedir/somefile", 0644);

// Everything for owner, read and execute for others
chmod("/somedir/somefile", 0755);

if($_POST['submit'] == 'Save')
{
    //Save the things
}

if( $_SERVER['REQUEST_METHOD'] == 'POST' and isset($_POST['submit']) )
{
    //Save the things
}

//Delay for some time
function delay()
{
    $sync_delay = get_option('sync_delay');

    echo "<br />Delaying for $sync_delay seconds...";
    sleep($sync_delay);
    echo "Done <br />";
}

//Delay for some time
function delay()
{
    static $sync_delay = null;

    if($sync_delay == null)
    {
	$sync_delay = get_option('sync_delay');
    }

    echo "<br />Delaying for $sync_delay seconds...";
    sleep($sync_delay);
    echo "Done <br />";
}

$_SESSION['username'] = $username;
$username = $_SESSION['username'];

define('APP_ID' , 'abc_corp_ecommerce');

//Function to get a session variable
function session_get($key)
{
    $k = APP_ID . '.' . $key;

    if(isset($_SESSION[$k]))
    {
        return $_SESSION[$k];
    }

    return false;
}

//Function set the session variable
function session_set($key , $value)
{
    $k = APP_ID . '.' . $key;
    $_SESSION[$k] = $value;

    return true;
}

function utility_a()
{
    //This function does a utility thing like string processing
}

function utility_b()
{
    //This function does nother utility thing like database processing
}

function utility_c()
{
    //This function is ...
}

class Utility
{
    public static function utility_a()
    {

    }

    public static function utility_b()
    {

    }

    public static function utility_c()
    {

    }
}

//and call them as 

$a = Utility::utility_a();
$b = Utility::utility_b();

if($a == true) $a_count++;

if($a == true)
{
    $a_count++;
}

foreach($arr as $c => $v)
{
	$arr[$c] = trim($v);
}

$arr = array_map('trim' , $arr);

$amount = intval( $_GET['amount'] );
$rate = (int) $_GET['rate'];

$db_records_in_array_format; 
//This is a big array holding 1000 rows from a table each having 20 columns , every row is atleast 100 bytes , so total 1000 * 20 * 100 = 2MB

$cc = $db_records_in_array_format; //2MB more

some_function($cc); //Another 2MB ?

$a = get_large_array();
pass_to_function(&$a);

class A
{
    function first()
    {
        $this->a = get_large_array();
        $this->pass_to_function();
    }

    function pass_to_function()
    {
        //process $this->a
    }
}

function add_to_cart()
{
    $db = new Database();
    $db->query("INSERT INTO cart .....");
}

function empty_cart()
{
    $db = new Database();
    $db->query("DELETE FROM cart .....");
}

$query = "INSERT INTO users(name , email , address , phone) VALUES('$name' , '$email' , '$address' , '$phone')";
$db->query($query); //call to mysqli_query()

function insert_record($table_name , $data)
{
    foreach($data as $key => $value)
    {
	//mysqli_real_escape_string
        $data[$key] = $db->mres($value);
    }

    $fields = implode(',' , array_keys($data));
    $values = "'" . implode("','" , array_values($data)) . "'";

    //Final query
    $query = "INSERT INTO {$table}($fields) VALUES($values)";

    return $db->query($query);
}

$data = array('name' => $name , 'email' => $email  , 'address' => $address , 'phone' => $phone);

insert_record('users' , $data);

<head>
<base href="http://www.domain.com/store/">
</head>
<body>
<img src="happy.jpg" />
</body>
</html>

<a href="home.php">Home</a>
<a href="products/ipad.php">Ipad</a>

<a href="../home.php">Home</a>
<a href="ipad.php">Ipad</a>

<a href="home.php">Home</a>
<a href="products/ipad.php">Ipad</a>

ini_set('display_errors', 1);
error_reporting(~E_WARNING & ~E_NOTICE & ~E_STRICT);

$ php -a
Interactive shell

php > echo strtotime("0000-00-00 00:00:00");
-62170005200
php > echo strtotime('1000-01-30');
-30607739600
php > echo strtotime('2100-01-30');
4104930600

set_time_limit(30);

//Rest of the code