Clement Rasul

Friday, October 18, 2013

SQL Query Form Design Pattern Using "MySQL PDO" driver

The following is a PHP Script that can serve as a design pattern for HTML form handling with "MySQL PDO" connection driver for the MySQL database.



<html>
<head>
<title>MySQL PDO Query Interface</title>
<!--
Clement L. Rasul
copyright (c) 2013
-->
</head>
<body>

<?php
$sql = trim($_POST['sql']);
$host = "localhost";
$user = "root";
$pw = "wordpass123";
$db = "testdb";

# Query Form
echo "<h1>MySQL PDO Query Interface</h1>";
echo "<form action='mysql_pdo_query.php' method='post'><textarea cols='80' rows='5' name='sql'>";
echo "$sql";
echo "</textarea><br /><input type='submit'></form>";

# Connection Check
try {
    $con = new PDO('mysql:host='.$host.';dbname='.$db.'', $user, $pw );
    $con->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
	echo "Database Status:  <font color='green'><blink><b>Connected...</b></blink></font><hr />";
} catch(PDOException $e) {
    echo 'ERROR: ' . $e->getMessage();
}

# SQL Query Script
$result = $con->query(''.$sql.'');
$num_rows = $result->rowCount();
$num_cols = $result->columnCount();
echo "Rows: ".$num_rows."<br />";
echo "Columns: ".$num_cols."<hr />";
echo "<table border='1'>";

# Table Heading
for ($i = 0; $i < $result->columnCount(); $i++) {
    $col = $result->getColumnMeta($i);
    $columns[] = $col['name'];
}

$f=0;
while ( $f < $num_cols ) {
	$fn = $columns[$f];
	echo "<th>".$fn."</th>";
	$f=$f+1;
    	}

# Table Content
while ( $row = $result->fetch(PDO::FETCH_NUM) ) {
	echo "<tr>";
	$c = 0;
	while ( $c < $num_cols ) {
		echo "<td>".$row[$c]."   </td.>";
		$c = $c+1;
		}
	echo "</tr>";
    	}
echo "</table>";

?>

</body>
</html>

SQL Query Form Design Pattern Using mysqli

The following is a PHP Script that can serve as a design pattern for HTML form handling with "mysqli" connection driver for the MySQL database.



<html>
<head>
<title>MySQL mysqli Query Interface</title>
<!--
Clement L. Rasul
copyright (c) 2013
-->
</head>
<body>

<?php
$sql = trim($_POST['sql']);
$host = "localhost";
$user = "root";
$pw = "wordpass123";
$db = "testdb";

# Query Form
echo "<h1>MySQL mysqli Query Interface</h1>";
echo "<form action='mysql_mysqli_query.php' method='post'><textarea cols='80' rows='5' name='sql'>";
echo "$sql";
echo "</textarea><br /><input type='submit'></form>";

# Connection Check
$testcon = mysqli_connect("$host", "$user", "$pw", "$db") or 
   die ("Database Status: <font color='red'><blink><b>Connection Error!</b></blink></font>");
echo "Database Status:  <font color='green'><blink><b>Connected...</b></blink></font><hr />";

# SQL Query Script
$con = new mysqli("$host", "$user", "$pw", "$db");
$result = $con->query("$sql");
$num_rows = $result->num_rows;
$num_cols = $result->field_count;
echo "Rows: ".$num_rows."<br />";
echo "Columns: ".$num_cols."<hr />";

# Table Heading
echo "<table border='1'>";
while ( $col = $result->fetch_field() ) {
	$fn = $col->name;
	echo "<th>".$fn."</th>";
    	}

# Table Content
while ( $row = $result->fetch_array() ) {
	echo "<tr>";
	$c = 0;
	while ( $c < $num_cols ) {
		echo "<td>".$row[$c]."   </td.>";
		$c = $c+1;
		}
	echo "</tr>";
    	}
echo "</table>";
?>

</body>
</html>

SQL Query Form Design Pattern Using mysql

The following is a PHP Script that can serve as a design pattern for HTML form handling with "mysql" connection driver for the MySQL database.



<html>
<head>
<title>MySQL mysql Query Interface</title>
<!--
Clement L. Rasul
copyright (c) 2013
-->
</head>
<body>

<?php
$sql = trim($_POST['sql']);
$host = "localhost";
$user = "root";
$pw = "wordpass123";
$db = "testdb";

# Query Form
echo "<h1>MySQL mysql Query Interface</h1>";
echo "<form action='mysql_mysql_query.php' method='post'><textarea cols='80' rows='5' name='sql'>";
echo "$sql";
echo "</textarea><br /><input type='submit'></form>";

# Connection Check
$con = mysql_connect( $host, $user, $pw );
mysql_select_db( $db , $con) or 
  die ("Database Status: <font color='red'><blink><b>Connection Error!</b></blink></font>");
echo "Database Status:  <font color='green'><blink><b>Connected...</b></blink></font><hr />";

# SQL Query Script
$result = mysql_query( $sql , $con) or die(mysql_error());
$num_rows = mysql_num_rows($result);
$num_cols = mysql_num_fields($result);
echo "Rows: ".$num_rows."<br />";
echo "Columns: ".$num_cols."<hr />";
echo "<table border='1'>";

# Table Heading
$f=0;
while ( $col = mysql_field_name($result, $f) ) {
	$fn = $col;
	echo "<th>".$fn."</th>";
	$f=$f+1;
    	}

# Table Content
while ( $row = mysql_fetch_array($result) ) {
	echo "<tr>";
	$c = 0;
	while ( $c < $num_cols ) {
		echo "<td>".$row[$c]."   </td.>";
		$c = $c+1;
		}
	echo "</tr>";
    	}
echo "</table>";

?>
</body>
</html>

Friday, July 19, 2013

User Authentication Using Squid

Prompting for username and password before allowing the user access to the Internet can be implemented in Squid by following the steps below:

1. Create the password file for Squid users

# touch /etc/squid3/squid-passwd
# chmod o+r /etc/squid3/squid-passwd

2. Add the Squid user

# htpasswd /etc/squid3/squid-passwd testuser

NEW PASSWORD:
RE-TYPE NEW PASSWORD:
Adding password for user testuser

3. Edit the Squid configuration file and add the following lines:

# nano /etc/squid3/squid.conf

----------------------------------

auth_param basic program /usr/lib/squid3/ncsa_auth /etc/squid3/squid-passwd

acl ncsa_users proxy_auth REQUIRED

http_access allow ncsa_users

----------------------------------

Save the file by pressing CTLR+O

4. Restart Squid

# /etc/init.d/squid3 restart

This procedure is tested on Ubuntu 11.04 and should work on most Linux distributions.

NOTE: User authentication does not work if the computer running Squid is configured as a transparent proxy.

Saturday, June 29, 2013

Configuring Ubuntu Linux Print Server using the CLI

You can configure print services using the command line. The following command will allow printing from clients on the same subnet:

# cupsctl --share-printers

If you want to print from any subnet, the CLI command is:

# cupsctl --share-printers --remote-any

If you want to specify the protocols to use for print sharing, the CLI command is:

# cupsctl ' BrowseLocalProtocols = "cups dnssd lpd smb" '

Disabling Services at Boot

Assuming you want to disable "squid" at boot, issue the command:

# update-rc.d -f squid remove

Sunday, May 19, 2013

How to burn iso image to USB

Assuming that your iso image file is located in "/home/clemrasul/linux.iso" and your USB is in "/dev/sdb", the Linux command to burn the image is:

#dd if=/home/clemrasul/linux.iso of=/dev/sdb

This command comes built-in in Linux.