Bagesh Singh's Blog » Php interview question http://www.bageshsingh.com/bagesh-blog Shortest Distance to Web Solutions & Software Solutions Wed, 22 Feb 2012 18:42:12 +0000 en hourly 1 http://wordpress.org/?v=3.2.1 How to optimize php code. http://www.bageshsingh.com/bagesh-blog/2011/09/how-to-optimize-php-code/ http://www.bageshsingh.com/bagesh-blog/2011/09/how-to-optimize-php-code/#comments Fri, 02 Sep 2011 20:40:19 +0000 Bagesh Singh http://www.bageshsingh.com/bagesh-blog/?p=1629 In this post we are  going to learn how to optimize our php code.

once you optimize your php code then your applicationa and website will be very fast
this will make quality code. Hi php programmer don’t forget these rules if you want to
be good in php and want to work in MNC because all mnc and all good companies follow
these rules strictly even this is gud question for interview for php. best of luck.

What is the process for PHP code Optimisation.

Use the Zend Optimizer and a code cache

Use the comma operator to join arguments when calling echo

Priorities optimisation of tight loops for the most payback

Pre-increment where possible

Don’t rely on references without testing; they are rarely as effective as you’d think

Get a good understanding of how garbage collection works

Listen to all errors, big and small – they slow things down

Store a local pointer to an array element to save indexing into the array each time you need it

Compress your output to save network bandwidth

Try to avoid using PHP in CGI mode

Avoid calling the dl() function

Use persistent resource where appropriate

Optimise compilation of your PHP binary if possible

Avoid mod_access if you can

Don’t fret about Apache 2.0

As a last resort, try inlining function

]]> http://www.bageshsingh.com/bagesh-blog/2011/09/how-to-optimize-php-code/feed/ 0 Please explain .frm .myd .myi in mysql? http://www.bageshsingh.com/bagesh-blog/2011/08/please-explain-frm-myd-myi-in-mysql/ http://www.bageshsingh.com/bagesh-blog/2011/08/please-explain-frm-myd-myi-in-mysql/#comments Mon, 29 Aug 2011 18:40:02 +0000 Bagesh Singh http://www.bageshsingh.com/bagesh-blog/?p=1599 Each MyISAM table is stored on disk in three files. The files have names that begin with the table name and have an extension to indicate the
file type.

  • The ‘.frm’ file stores the table definition.
  • The data file has a ‘.MYD’ (MYData) extension.
  • The index file has a ‘.MYI’ (MYIndex) extension.
]]> http://www.bageshsingh.com/bagesh-blog/2011/08/please-explain-frm-myd-myi-in-mysql/feed/ 0 What Is the Difference Between Mysql_Connect() and Mysql_Pconnect()? http://www.bageshsingh.com/bagesh-blog/2011/08/what-is-the-difference-between-mysql_connect-and-mysql_pconnect/ http://www.bageshsingh.com/bagesh-blog/2011/08/what-is-the-difference-between-mysql_connect-and-mysql_pconnect/#comments Mon, 29 Aug 2011 18:38:11 +0000 Bagesh Singh http://www.bageshsingh.com/bagesh-blog/?p=1591 When they are using mysql_connect() function, every time it is opening and closing the database connection, depending on the request .

mysql_connect() and mysql_pconnect() both are working for database connection but with small difference. In mysql_pconnect(), ‘p’ stands for persistence connection.

But in case of mysql_pconnect() function,
first, when connecting, the function would try to find a (persistent) connection that’s already open with the same host, username and password. If three is found, an identifier for it will be returned in lieu of opening a new connection.
Second, the connection to the SQL server won’t be closed when the execution of the script ends. In lieu, the connection will remain open for future use (mysql_close() won’t close connection established by mysql_pconnect()).

Mysql_pconncet() is useful when you have a lot of traffic on your site. At that time for every request it won’t open a connection but will take it from the pool. This will increase the efficiency of your site. But for general use mysql_connect() is best.

]]> http://www.bageshsingh.com/bagesh-blog/2011/08/what-is-the-difference-between-mysql_connect-and-mysql_pconnect/feed/ 0 How to Connect to MySQL Database Using PHP? http://www.bageshsingh.com/bagesh-blog/2011/08/how-to-connect-to-mysql-database-using-php/ http://www.bageshsingh.com/bagesh-blog/2011/08/how-to-connect-to-mysql-database-using-php/#comments Mon, 29 Aug 2011 18:37:25 +0000 Bagesh Singh http://www.bageshsingh.com/bagesh-blog/?p=1589
<?php
$username = "your_name";
$password = "your password";
$hostname = "localhost";
$dbname = "database name";
//Connection to the MySql Database
$dbhandle = mysql_connect($hostname, $username, $password)
 or die("Unable to connect to MySQL");
mysql_select_db("$dbname",$db);
echo "Connected to MySQL";
?>
]]> http://www.bageshsingh.com/bagesh-blog/2011/08/how-to-connect-to-mysql-database-using-php/feed/ 0 CURL URLS with a get variable http://www.bageshsingh.com/bagesh-blog/2011/08/curl-urls-with-a-get-variable/ http://www.bageshsingh.com/bagesh-blog/2011/08/curl-urls-with-a-get-variable/#comments Mon, 29 Aug 2011 18:34:19 +0000 Bagesh Singh http://www.bageshsingh.com/bagesh-blog/?p=1580 I had the following experience when harvesting urls with a get variable from a page using cUrl. HTML pages will output ampersands as &amp when the page is read by the curl function.

If you code a script to find all hyperlinks, it will use &amp instead of &, especially using a regular expression search.

It is hard to detect because when you output the url to the browser it renders the html. To fix, add a line to replace the &amp with &.

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<?php
function processURL($url){
    $url=str_replace('&amp;','&',$url);
    $ch=curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1);
    $xml = curl_exec ($ch);
    curl_close ($ch);
    echo $xml;
}
?>
]]> http://www.bageshsingh.com/bagesh-blog/2011/08/curl-urls-with-a-get-variable/feed/ 0 CURL PHP wrapper for https results http://www.bageshsingh.com/bagesh-blog/2011/08/curl-php-wrapper-for-https-results/ http://www.bageshsingh.com/bagesh-blog/2011/08/curl-php-wrapper-for-https-results/#comments Mon, 29 Aug 2011 18:33:52 +0000 Bagesh Singh http://www.bageshsingh.com/bagesh-blog/?p=1578 If you want to write a sort of php wrapper to include the results of another http(s) request maybe pointing to a totally different site or just different code (mod_perl with HTML::Mason, in my case) into a php based layout, and just pass-thru all GET and POST variables to the sub-request, the following snippet can be used. Note there is no error handling, so this is subject to the underlying application.

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<?php
$ch = curl_init($sub_req_url);
$encoded = '';
// include GET as well as POST variables; your needs may vary.
foreach($_GET as $name => $value) {
  $encoded .= urlencode($name).'='.urlencode($value).'&';
}
foreach($_POST as $name => $value) {
  $encoded .= urlencode($name).'='.urlencode($value).'&';
}
// chop off last ampersand
$encoded = substr($encoded, 0, strlen($encoded)-1);
curl_setopt($ch, CURLOPT_POSTFIELDS,  $encoded);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_POST, 1);
curl_exec($ch);
curl_close($ch);
?>
]]> http://www.bageshsingh.com/bagesh-blog/2011/08/curl-php-wrapper-for-https-results/feed/ 0 CURL PHP: Get information regarding a specific transfercurl_getinfo — Get information regarding a specific transfer – curl_getinfo() http://www.bageshsingh.com/bagesh-blog/2011/08/curl-php-get-information-regarding-a-specific-transfercurl_getinfo-ae%e2%80%9d-get-information-regarding-a-specific-transfer-%e2%80%93-curl_getinfo/ http://www.bageshsingh.com/bagesh-blog/2011/08/curl-php-get-information-regarding-a-specific-transfercurl_getinfo-ae%e2%80%9d-get-information-regarding-a-specific-transfer-%e2%80%93-curl_getinfo/#comments Mon, 29 Aug 2011 18:33:25 +0000 Bagesh Singh http://www.bageshsingh.com/bagesh-blog/?p=1576
<?php
// Create a curl handle
$ch = curl_init('http://www.yahoo.com/');
// Execute
curl_exec($ch);
// Check if any error occured
if(!curl_errno($ch))
{
 $info = curl_getinfo($ch);
 echo 'Took ' . $info['total_time'] . ' seconds to send a request to ' . $info['url'];
}
// Close handle
curl_close($ch);
?>
]]> http://www.bageshsingh.com/bagesh-blog/2011/08/curl-php-get-information-regarding-a-specific-transfercurl_getinfo-ae%e2%80%9d-get-information-regarding-a-specific-transfer-%e2%80%93-curl_getinfo/feed/ 0 Example: Download Website / Webpage Trough CURL PHP http://www.bageshsingh.com/bagesh-blog/2011/08/example-download-website-webpage-trough-curl-php/ http://www.bageshsingh.com/bagesh-blog/2011/08/example-download-website-webpage-trough-curl-php/#comments Mon, 29 Aug 2011 18:33:04 +0000 Bagesh Singh http://www.bageshsingh.com/bagesh-blog/?p=1574 You can access / display any webpage through the following code:

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<?php
    echo DownloadUrl('http://www.imjan.com'); // Type Website URL to download
    function DownloadUrl($Url){
            // is curl installed?
            if (!function_exists('curl_init')){
                    die('CURL is not installed!');
            }
            // create a new curl resource
            $ch = curl_init();
            /*
            Here you find more options for curl:
            */
            // set URL to download
            curl_setopt($ch, CURLOPT_URL, $Url);
            // set referer:
            curl_setopt($ch, CURLOPT_REFERER, "http://www.google.com/");
            // user agent:
            curl_setopt($ch, CURLOPT_USERAGENT, "MozillaXYZ/1.0");
            // remove header? 0 = yes, 1 = no
            curl_setopt($ch, CURLOPT_HEADER, 0);
            // should curl return or print the data? true = return, false = print
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
            // timeout in seconds
            curl_setopt($ch, CURLOPT_TIMEOUT, 10);
            // download the given URL, and return output
            $output = curl_exec($ch);
            // close the curl resource, and free system resources
            curl_close($ch);
            // print output
            return $output;
    }
?>
]]> http://www.bageshsingh.com/bagesh-blog/2011/08/example-download-website-webpage-trough-curl-php/feed/ 0 CURL PHP: Email this page to a friend http://www.bageshsingh.com/bagesh-blog/2011/08/curl-php-email-this-page-to-a-friend/ http://www.bageshsingh.com/bagesh-blog/2011/08/curl-php-email-this-page-to-a-friend/#comments Mon, 29 Aug 2011 18:32:29 +0000 Bagesh Singh http://www.bageshsingh.com/bagesh-blog/?p=1572 Using curl to take snapshots of the current page for emailing the HTML is a clever little idea. (ie: Email this page to a friend)

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<?php
//to be explained below!
session_write_close();
$pageurl = "http://www.site.com/content.php?PHPSESSID=123XYZ
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt ($ch, CURLOPT_URL, $pageurl );
$html = curl_exec ( $ch );
curl_close($ch);
//then you need to fix pathing to absolute
$search = "/(src|href|background)="[^:,^>,^\"]*\"/i";
preg_match_all ( $search, $html, $a_matches );
//you can figure out the rest ! but thought the reg expression is useful as well
?>

But here is the catch, you may want to make sure curl connects to the server under the same session as the browser. So naturally you pass the session cookie through the curl system either by the cookie jar system, or through the query string in the path.

This is where you will get stuck. PHP will need write access to the same session file simultaneously!! causing serious hanging issues!

This is why you should close off your session before you make curl take a page snapshot!

]]> http://www.bageshsingh.com/bagesh-blog/2011/08/curl-php-email-this-page-to-a-friend/feed/ 0 cURL to submit to an ASP/ASPX page http://www.bageshsingh.com/bagesh-blog/2011/08/curl-to-submit-to-an-aspaspx-page/ http://www.bageshsingh.com/bagesh-blog/2011/08/curl-to-submit-to-an-aspaspx-page/#comments Mon, 29 Aug 2011 18:31:58 +0000 Bagesh Singh http://www.bageshsingh.com/bagesh-blog/?p=1570 For anyone trying to use cURL to submit to an ASP/ASPX page that uses an image as the submit button.

Make sure that you have ‘button_name.x’ and ‘button_name.y’ in the post fields. PHP names these fields ‘button_name_x’ and ‘button_name_y’, while ASP uses a dot.

Also, as noted above, be sure to include the ‘__VIEWSTATE’ input field in your post request.

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