PHP tips and tricks

PHP tips and tricks Skien, Norge, June 7th 2007

Agenda Tips and Tricks from PHP No need for anything else than standard distribution All for PHP 5 ( but lots of it is also valid in PHP 4 ) The month of PHP functions

Who is speaking? Damien Séguy Nexen Services, eZ publish silver partner for hosting PHP / MySQL services Redacteur en chef of www.nexen.net Phather of an plush Elephpant http://www.nexen.net/english.php

Nod when you know about it

Random stuff rand() and mt_rand() array_rand() : extract info from an array extract keys! shuffle() : shuffle an array before deal str_shuffle() : shuffle a string

Random stuﬀ Array <?php ( $a = range('a','d'); [0] => c shuffle($a); [1] => d [2] => b print_r($a); [3] => a ) print_r(array_rand($a,3)); Array ( print str_shuffle('abcdef'); [0] => 0 // eabdcf [1] => 1 ?> [2] => 3 )

Arrays combinaisons array_combine() : turn two arrays into one Inverse to array_keys() and array_values() <?php $a = array('green', 'red', 'yellow'); $b = array('avocado', 'apple', 'banana'); $c = array_combine($a, $b); Array print_r($c); ( ?> [green] => avocado [red] => apple [yellow] => banana )

Arrays combinaisons array_combine() : turn two arrays into one PDO::FETCH_KEY_PAIR : combine 2 columns in a hash <?php $html = file_get_contents(quot;http://www.php.net/quot;); //'<a href=quot;http://php.netquot;>PHP</a>'; if (preg_match_all( '#<a href=quot;(http://[^quot;/?]+/).*?>(.*?)</a>#s', $html, $r)) { $liste = array_combine($r[2], $r[1]); } print_r($liste); ?>

Arrays as SQL array_count_values() : makes easy stats Works like a GROUP BY and COUNT() <?php $array = array(1, quot;heiquot;, 1, quot;takkquot;, quot;heiquot;); print_r(array_count_values($array)); ?> Array ( sort r u [1] => 2 r u [hei] => 2 k k kr uk [takk] => 1 a a ar ua )

Arrays as SQL Array ( array_multisort() : sort several [0] => 2 arrays at once [1] => 3 [2] => 4 Works like a ORDER BY [3] => 5 <?php ) $ar1 = array(5,4,3,2); Array $ar2 = array('a','b','c','d'); ( array_multisort($ar1, $ar2); [0] => d array_multisort($ar1, [1] => c SORT_ASC,SORT_STRING, [2] => b $ar2); [3] => a ?> )

Fast dir scans scandir(‘/tmp’, true); Include name sorting Replace opendir, readdir, closedir and a loop! glob(‘*.html’); Simply move the loop out of sight

Fast dir scans Array ( [0] => sess_um8rgjj10f6qvuck91rf36srj7 [1] => sess_u58rgul68305uqfe48ic467276 [2] => mysql.sock <?php [3] => .. print_r(scandir('/tmp/', 1)); [4] => . print_r(glob('/tmp/sess_*')); ) ?> Array ( [0] => /tmp/sess_um8rgjj10f6qvuck91rf36srj7 [1] => /tmp/sess_u58rgul68305uqfe48ic467276 )

URL operations parse_url() break down into details do not make any check parse_str() split a query string separate and decode, as long as it can Fill up an array or globals

URL <?php $url = 'http://login:pass@www.site.com/ path/file.php?a=2+&b%5B%5D= %E5%AF%B9%E4%BA%86%EF%BC%81#ee'; $d = parse_url($url); print_r($d); parse_str($d[quot;queryquot;]); var_dump($GLOBALS[quot;bquot;]); ?>

URL ( [scheme] => http [host] => www.site.com [user] => login [pass] => pass [path] => /path/file.php [query] => a=2&b%5B%5D=%E5%AF%B9%E4%BA%86%EF%BC%81 [fragment] => ee ) array(1) { [0]=> string(9) quot; quot; }

URL validations scheme : list your own host : checkdnsrr() to check path : realpath() + doc root (beware of mod_rewrite) query : parse_str() beware of the second argument! don’t handle &

URL rebuilding http_build_query() rebuild your query takes into account encoding and arrays <?php print http_build_query( array_merge($_GET , array(' de ' => ' '))); ?> +de+=%E5%AF%B9%E4%BA%86%EF%BC%81

URL testing <?php get_headers('http://localhost/logo.png'); ?> Array ( [0] => HTTP/1.1 200 OK [1] => Date: Mon, 12 Feb 2007 02:24:23 GMT [2] => Server: Apache/1.3.33 (Darwin) PHP/5.2.1 [3] => X-Powered-By: eZ publish [4] => Last-Modified: Fri, 30 Sep 2005 09:11:28 GMT [5] => ETag: quot;f6f2a-dbb-433d0140quot; [6] => Accept-Ranges: bytes [7] => Content-Length: 3515 [8] => Connection: close [9] => Content-Type: image/png )

PHP is dynamic Variables variables <?php $x = 'y'; $y = 'z'; $z = 'a'; echo $x; // displays y echo $$x; // displays z echo $$$x; // displays a ?>

Variable constants Still one deﬁnition Dynamic constant value <?php define (quot;CONSTANTquot;, 'eZ Conference'); echo CONSTANT; echo constant(quot;CONSTANTquot;); ?> See the runkit to change constants...

Juggling with variables Compact() and extract() <?php $x = 'a'; $y = 'b'; $z = compact('x','y'); // $z = array('x'=> 'a', 'y' => 'b'); $r = call_user_func_array('func', $z); // calling func($x, $y); extract($r); // $x = 'c'; $y = 'd'; $t = 'e'; list($x, $y, $t) = array_values($r); ?>

Variable functions <?php $func = 'foo'; $foo = 'bar'; $class = 'bb'; $func($foo); // calling foo with bar call_user_func($func, $foo);// same as above call_user_func(array($class, $func), $foo); // now with objects! $class->$func($foo); // same as above ?>

Variable functions <?php $func = 'f'; // a function // beware of langage construct such as empty() $func = array('c','m'); // a static call to class c $func = array($o,'m'); // a call to object o call_user_func($func, $foo); ?>

Object magic __autoload() : load classes JIT __sleep() and __wakeup() Store object and ressources in sessions __toString() : to turn an object to a string __toArray() : get_object_vars($object); __toInteger() : may be?

Output buﬀering Avoid ‘already sent’ bug Clean it : tidy <?php Compress it : gz ob_start(quot;ob_gzhandlerquot;); Cache it echo quot;Hellonquot;; setcookie(quot;cquot;, quot;vquot;); ob_end_flush(); ?>

Caching auto_prepend : if ( filemtime($cache)+3600 < time()) { include($cachefile); exit; } ob_start(); auto_append : $content = ob_get_contents(); file_put_contents('cache', $contents); ob_end_flush(); Auto-caching upon 404 error pages

Connexion handling PHP maintains the connexion status 0 Normal; 1 Aborted; 2 Timeout ignore_user_abort() to make a script without interruption connexion_status() to check status

Register for shutdown Function executed at script shutdown Correct closing of resources More convenient than ignore_user_abort() a library In OOP, better use __destruct() Storing calculated variables

Variables export var_export() : recreate PHP code for a variable <?php array ( 0 => 5, $array = array(5,4,3,2); 1 => 4, 2 => 3, file_put_contents('file.inc.php', 3 => 2, '<?php $x = '. ) var_export($array, true). '; ?>' ); ?>

Assertions Include tests during execution Assertion are an option (default is on) : Most clever way than removing than echo/var_dump Common practice in other languages Programmation by contract

Assertions <?php assert_options(ASSERT_CALLBACK,'assert_callback'); function assert_callback($script,$line, $message){ echo 'There is something strange in your script ', $script,' : line ', $line,' : '; exit; } assert('is_integer( $x );' ); assert('($x >= 0) && ($x <= 10); //* $x must be from 0 to 10' ); echo quot;0 <= $x <= 10quot;; ?>

Debugging get_memory_usage() memory_limit is now on by default Better memory handling The fake growth of memory needs get_peak_memory_usage()

Debugging get_included_files() get_defined_constants/functions/vars() get_declared_classes() get_debug_backtrace() function stack and their arguments file and line calling

Debugging array(2) { [0]=> array(4) { [quot;filequot;] => string(10) quot;/tmp/a.phpquot; [quot;linequot;] => int(10) [quot;functionquot;] => string(6) quot;a_testquot; [quot;argsquot;]=> array(1) { [0] => &string(6) quot;friendquot; } } [1]=> array(4) { [quot;filequot;] => string(10) quot;/tmp/b.phpquot; [quot;linequot;] => int(2) [quot;argsquot;] => array(1) { [0] => string(10) quot;/tmp/a.phpquot; } [quot;functionquot;] => string(12) quot;include_oncequot; } }

Slides http://www.nexen.net/english.php damien.seguy@nexen.net http://www.nexenservices.com/

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PHP tips and tricks

by Seguy Damien on Jun 08, 2007

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