How to Save bandwidth

To save bandwidth add the following code at the beginning of your PHP page, and then PHP will automatically compress the page to web browsers that support with feature (support in both Internet Explorer and Mozilla Firefox do).
Since HTML can easily be compressed, you can expect to cut down by at least 2/3 the bandwidth used at the expense of some extra load on the server's CPU, but the CPU load difference usually isn't even noticeable.

@ini_set('zlib.output_compression_level', 1);
@ob_start('ob_gzhandler');

What is CAPTCHA?

CAPTCHA stands for Completely Automated Public Turing Test to tell Computers and Humans Apart. CAPTCHA use for prevent spammers from using bots to automatically fill out forms, CAPTCHA programmers will generate an image containing distorted images of a string of numbers and letters. Computers or bot cannot determine what the numbers and letters are from the image but humans have great pattern recognition abilities and will be able to fairly accurately determine the string of numbers and letters. By entering the numbers and letters from the image in the validation field, the application can be fairly assured that there is a human client using it.
You can get more info here:
http://en.wikipedia.org/wiki/Captcha

What are the advantages of stored procedures, triggers, indexes?

Stored procedure : Stored procedureis a set of SQL commands that can be compiled and stored in the server. Once this process has been done, user don’t need to keep re-issuing the entire query he can refer to the stored procedure. This provides better overall performance because the query has to be parsed only once and less information needs to be sent between the server and the user. We can also raise the conceptual level by having libraries of functions in the server. However, stored procedures of course do increase the load on the database server system, as more of the work is done on the server side and less on the client (application) side.

Trigger : A trigger is effectively a type of stored procedure, one that is invoked when a particular event occurs. For example, we can install a stored procedure that is triggered each time a record is deleted from a transaction table and that stored procedure automatically deletes the corresponding customer from a customer table when all his transactions are deleted.

Indexes : Indexes are used to find rows with specific column values quickly. Without an index, MySQL must begin with the first row and then read through the entire table to find the relevant rows. The larger the table, the more this costs. If the table has an index for the columns in question, MySQL can quickly determine the position to seek to in the middle of the data file without having to look at all the data. If a table has 1,000 rows, this is at least 100 times faster than reading sequentially. If you need to access most of the rows, it is faster to read sequentially, because this minimizes disk seeks.

How to Extract Domain name from URL ?

Here is a simple example describe below.

“parse_url” function can be used to parse the URL.

parse_url is a built in php function which can be used to parse url and get the type of request like whether its http or https or ftp, gives the domain name like www.example.com and path and the query.

eg. consider this url – “http://www.example.com/page.php?id=1”

In “http://www.example.com/page.php?id=1” this url if you execute parse_url function then it will show the following result.

Scheme - http
url - www.example.com
path - /page.php
query - id=1

How to Unlink all files and folder in a particular folder?

Basically we use "unlink" to delete a file physically.
The syntax is unlink(file path including file name).

But if we want to delete all files and folder of a perticular folder then we can use this code

// arguments : The target directory , delete directory or leave it blank (true/false)
// return : none

function removeAll ($dir, $delDir) {
if(!$dh = @opendir($dir)) return;
while (false !== ($obj = readdir($dh))) {
if($obj=='.' || $obj=='..') continue;
if (!@unlink($dir.'/'.$obj)) removeAll ($dir.'/'.$obj, true);
}
if ($delDir){
closedir($dh);
@rmdir($dir);
}
}

Note: Please change folder permission (0777) before excuting the code

What is Crawler and Indexer

Crawler and Indexer

Typically the crawler is the component of the search engine responsible for going out and retrieving
content for the indexer to catalog. It reads the list of addresses from the database and downloads a copy
of each document to queue locally to disk where the indexer can access them. Then the indexer
component processes each file in the queue. This tag - team approach works well for large search sites
with massive amounts of data continuously being indexed or if the crawler scans through the documents
in search of links to other documents to retrieve (as is the case with recursive downloading/leeching).

Difference between section and foreach loop in Smarty

The main difference between SECTION and FOREACH is that

1.For SECTION you can start from a specific value, and can also set a step for the iteration, whereas for FOREACH you have to loop over all values.

2.foreach is used for associative arrays

Array Functions : How to insert an element or remove an element from an array

In this process you can insert an element or remove an element from an array


$numbers = array(1,2,3,4,5,6);
print_r($numbers);
echo "

";

// shifts first element out of an array
// and returns it.
$a = array_shift($numbers);
echo "a:" . $a ."
";
print_r($numbers);
echo "

";

// prepends an element to an array,
// returns the element count.
$b = array_unshift($numbers, 'first');
echo "b: ". $b ."
";
print_r($numbers);
echo "

";

echo "

---

";

// pops last element out of an array
// and returns it.
$a = array_pop($numbers);
echo "a: " . $a ."
";
print_r($numbers);
echo "

";

// pushes an element onto the end of an array,
// returns the element count.
$b = array_push($numbers, 'last');
echo "b: ". $b ."
";
print_r($numbers);
echo "

";

Import mysql data to excel

// Connect database.
mysql_connect("localhost","","");
mysql_select_db("import");

// Get data records from table.
$result=mysql_query("select * from name_list order by id asc");

// Functions for export to excel.
function xlsBOF() {
echo pack("ssssss", 0x809, 0x8, 0x0, 0x10, 0x0, 0x0);
return;
}
function xlsEOF() {
echo pack("ss", 0x0A, 0x00);
return;
}
function xlsWriteNumber($Row, $Col, $Value) {
echo pack("sssss", 0x203, 14, $Row, $Col, 0x0);
echo pack("d", $Value);
return;
}
function xlsWriteLabel($Row, $Col, $Value ) {
$L = strlen($Value);
echo pack("ssssss", 0x204, 8 + $L, $Row, $Col, 0x0, $L);
echo $Value;
return;
}
header("Pragma: public");
header("Expires: 0");
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("Content-Type: application/force-download");
header("Content-Type: application/octet-stream");
header("Content-Type: application/download");;
header("Content-Disposition: attachment;filename=orderlist.xls ");
header("Content-Transfer-Encoding: binary ");

xlsBOF();

/*
Make a top line on your excel sheet at line 1 (starting at 0).
The first number is the row number and the second number is the column, both are start at '0'
*/

xlsWriteLabel(0,0,"List of car company.");

// Make column labels. (at line 3)
xlsWriteLabel(2,0,"No.");
xlsWriteLabel(2,1,"Company");

$xlsRow = 3;

// Put data records from mysql by while loop.
while($row=mysql_fetch_array($result)){

xlsWriteNumber($xlsRow,0,$row['id']);
xlsWriteLabel($xlsRow,1,$row['name']);

$xlsRow++;
}
xlsEOF();
exit();

Calculate Visitor Counter

Follow the step
1. Create a file name "visitcount.dat"
2. Upload the file in webserver
3. make file permission CHMOD *777*
Now Insert the PHP code below


$counterfile = "visitcount.dat";
if(!($fp = fopen($counterfile,"r"))) die ("cannot open counter file");
$count = (int) fread($fp, 20);
fclose($fp);
$count++;
echo "Total hit counter: $count";
$fp = fopen($counterfile, "w");
fwrite($fp , $count);
fclose($fp);