See Apache Webserver Tips

var was the keyword for defining a member variable within a class. Since php5 it should never appear anywhere.

For hashtables use this syntax:

echo "A banana is {$fruits['banana']}.";

• __FILE__: The full path and filename of the file, see language.constants.predefined
• $_SERVER['PHP_SELF']: filename of the currently executing script, relative to the document root, see reserved.variables
• HTTP POST variables: $_POST

Arrays - Array Functions

$fruits = array (
  "fruits"  => array ("a"=>"orange", "b"=>"banana", "c"=>"apple"),
  "numbers" => array (1, 2, 3, 4, 5, 6),
  "holes"   => array ("first", 5 => "second", "third")
);

foreach ($fruits as $fruit) {...}         // traverse the array
foreach ($fruits as $key => $fruit) {...} // same if indices are needed
$length= count($fruits); // get number of items
print_r($fruits);        // print content

Access to a nonexisting key generates a PHP notice. To prevent this, you can check before the access if the key exists or if the value is set. More

array_key_exists('key', $fruits)) // returns true if the key exists
isset($fruits['key']) // returns true if the key exists AND value != NULL

By default, arrays are copied by value (Unlike PHP objects and Java arrays and objects):

$a=array(0);
 
$b= $a;  /* Deep copy: Assignment by value */
$b[0]= 1;
assert($a[0] == 0);
 
$c= &$a; /* Shallow copy: Assignment by reference */
$c[0]= 2;
assert($a[0] == 2);
$a[0]= 3;
assert($c[0] == 3);
 
$d= $c;  /* $c is not different from $a: Again assignment by value */
$d[0]= 4;
assert($a[0] == 3);
assert($c[0] == 3);

function f($v)  { $v[0]= 1; }
function g(&$w) { $w[0]= 2; }
function h(&$x) { $x[0]= 3; return $x; }
$a= array(0);
 
f($a);     /* pass-by-value */
assert($a[0] == 0);
 
f(&$a); /* Call-time pass-by-reference works, but is deprecated! */
assert($a[0] == 1);
 
g($a);     /* pass-by-reference */
assert($a[0] == 2);
 
$b= h($a);          /* return-by-reference seems to be default */
assert($a[0] == 3); /* (pass-by-reference just to make it verifiable) */

$a= array(0);
$b= array('d'=> $a, 'e'=> &$a);
 
$a[0]= 1;
assert($b['d'][0] == 0);
assert($b['e'][0] == 1);

class C {
    public function f(&$v) { $this->v=  $v; $this->v[0]= 1; }
    public function g(&$w) { $this->w= &$w; $this->w[0]= 2; }
}
$o= new C();
$a= array(0);
 
$o->f($a);
assert($a[0] == 0);
 
$o->g($a);
assert($a[0] == 2);

Objects are copied by „something like a reference“ more. This means the reference operator is not necessary for ojects (anlike PHP arrays)

Add some code to prove this.

Use error_log() for debug logging.

2004-02-13 14:45

• see also php-docu: capter „Using Php from the command line“
• /usr/bin/php can be CLI- or CGI- Sapi; test it with „php -v“
• Only If CGI:
  • Optin -qC is necessary in shebang; therefore use it BY DEFAULT! (-q suppresses header; -C keeps working dir)
  • set register_argc_argv = On in /etc/apache/php.ini

#!/usr/bin/php
<?php
echo "argument count: ".$_SERVER['argc']."\n";
foreach ($_SERVER['argv'] as $name => $value) {
    echo "$name: $value\n";
}
?>

Script saved as tester and called with tester bee fly prints:

argument count: 3
0: /home/becki/bin/tester
1: bee
2: fly

argv[0] = name of script
Dont't use $arc and $argv, because they are not available under all circumstances!

Read stdin line by line into the array lin:

char lin[MAX_LINE_LEN];
while (fgets(lin, MAX_LINE_LEN, stdin)) {/* do some thing */}

printf(); echo; // writing to stdout
;  // writing to stderr
error_log("Value $val"); // writing to System error log eg. /var/log/apache/error_log

Pre- and Postactions are probably obsolete. See http://skiclub-mitwitz.de/lib/libPage/

See also: Build your own MVC Framework

1. Every page must have exactly 1 unique pre-action (prefix) which is used for building the page eg a database query
2. Pages can only be accessed by their pre-actions not directly by other pages. If the page has no dynamic content, the pre-action just calls the page constructor or sets the $page global variable.
3. Although different pages may require to do the same things in it's pre-actions do not use the same action, but let those actions call the same helper function. Thus the target page becomes clear.
4. pre-action can change page by calling other pre-action

1. Each link or form of a page may be bound to exactly 1 unique post-action (suffix) eg a database update
2. Post-actions may be followed by pre-actions (chaining of actions)
3. Actions are named after the page they are bound to. To the name of pre-actions 'p_' is prepended and to post-actons (suffixes) 's_' is prepended
4. Use a parameter called eg 'target' for (the pre-actions of) pages wich can be called by differnt other pages and have to jump back to ther calling pages after they are left.

This section is in progress

• Google Buchsuche
• http://www.devshed.com/cp/bio/David-Web/
• Dokuwiki sourcode
• http://en.wikipedia.org/wiki/HTTP_cookie#Authentication
• http://pear.php.net/distributions/manual/pear_manual_en.html.gz#package.authentication.auth.intro

• Check out: Sending Email with PHP and Practical PHP: Sending E-mail
• Check out: http://www.php.net/autoload
• Check active record pattern for database access