Make a Search Engine For Your Website With PHP

This hands on PHP Programming article provides the knowledge necessary to design and develop a search engine for your website using PHP version 4.0 and above. Making a search engine for your website with PHP is really easy and provides substantial functionality required by most of the small to medium websites. This article introduces every steps of the development, including both design and PHP programming. Basic computer skills and knowledge of HTML fundamentals are required. Ok, let’s begin now.
Step 1: Design Search Box
Under your website root, make a file called search.htm or anything you like and type in the following code:
<html>
<head>
<title>Web Search</title>
<meta http-equiv="Content-Type" content="text/html">
</head>
<body bgcolor="#FFFFFF" text="#000000">
<form name="form1" method="post" action="search.php">
<table width="100%" cellspacing="0" cellpadding="0">
<tr>
<td width="36%">
<div align="center">
<input type="text" name="keyword">
</div>
</td>
<td width="64%">
<input type="submit" name="Submit" value="Search">
</td>
</tr>
</table>
</form>
</body>
</html>
Step 2: Write search.php file. It is the core of your website search engine.
Under your website root, create a file called search.php or anything you like.
<?php
//get keywords
$keyword=trim($_POST["keyword"]);
//check if the keyword is empty
if($keyword=="")
echo"no keywords";
exit;
}
?>
With above, you can give hints to your users when they forget to enter a keyword. Now let’s go through all the files or articles in your website.
<?php
function listFiles($dir)
$handle=opendir($dir);
while(false!==($file=readdir($handle)))
if($file!="."&&$file!="..")
//if it is a directory, then continue
if(is_dir("$dir/$file"))
listFiles("$dir/$file");
}
else
//process the searching here with the following PHP script
}
}
}
}
?>
The following scripts read, process files and check whether the files contain $keyword. If $keyword is found in the file, the file address will be saved in an array-type variable.
<?php
function listFiles($dir,$keyword,&$array)
$handle=opendir($dir);
while(false!==($file=readdir($handle)))
if($file!="."&&$file!="..")
if(is_dir("$dir/$file"))
listFiles("$dir/$file",$keyword,$array);
}
else
//read file
$data=fread(fopen("$dir/$file","r"),filesize("$dir/$file"));
//avoid search search.php itself
if($file!="search.php")
//contain keyword?
if(eregi("$keyword",$data))
$array[]="$dir/$file";
}
}
}
}
}
}
//define array $array
$array=array();
//execute function
listFiles(".","php",$array);
//echo/print search results
foreach($array as $value)
echo "$value"."<br>n";
}
?>
Now, combine the programs listed above, you will find all the related results in your websites will be found and listed. A further optimization of the search engine can be taken by adding the following,
1,list the title of all searching results
REPLACE THE FOLLOWING
if(eregi("$keyword",$data))
$array[]="$dir/$file";
}
WITH
if(eregi("$keyword",$data))
if(eregi("<title>(.+)
</title>",$data,$m))
$title=$m["1"];
}
else
$title="no title";
}
$array[]="$dir/$file $title";
}
2,Add links to searching results
CHANGE THE FOLLOWING
foreach($array as $value)
echo "$value"."<br>n";
}
TO
foreach($array as $value)
list($filedir,$title)=split("[ ]",$value,"2");
echo "<a href=$filedir>$value</a>"."<br>n";
}
3 Set time limit for PHP execution
ADD THE FOLLOWING AT THE BEGINNING OF PHP FILES
set_time_limit("600");
The above unit is second,so ten minutes is the litmit.
Now, combine all the above programs and get the complete search.php file as following,
<?php
set_time_limit("600");
$keyword=trim($_POST["keyword"]);
if($keyword=="")
echo"Please enter your keyword";
exit;
}
function listFiles($dir,$keyword,&$array)
$handle=opendir($dir);
while(false!==($file=readdir($handle)))
if($file!="."&&$file!="..")
if(is_dir("$dir/$file"))
listFiles("$dir/$file",$keyword,$array);
}
else
$data=fread(fopen("$dir/$file","r"),filesize("$dir/$file"));
if(eregi("<body([^>]+)>(.+)</body>",$data,$b))
$body=strip_tags($b["2"]);
}
else
$body=strip_tags($data);
}
if($file!="search.php")
if(eregi("$keyword",$body))
if(eregi("<title>(.+)</title>",$data,$m))
$title=$m["1"];
}
else
$title="no title";
}
$array[]="$dir/$file $title";
}
}
}
}
}
}
$array=array();
listFiles(".","$keyword",$array);
foreach($array as $value)
list($filedir,$title)=split("[ ]",$value,"2");
echo "<a href=$filedir target=_blank>$title </a>"."<br>n";
}
?>
Now, you have made a search engine for your website, enjoy it!

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