Lesson 11 - PHP Advanced (2)

Connecting to database with PHP

o PHP interface is very friendly. 
o The methods embedded within PHP, and you don't need 
  to import modules for this.
o List of methods (there are many) can be found here

snp.php
See a demo
# Connecting to the DB server. If succeeded 
# returns a linker object, otherwise returns false.
# The arguments are: host, user, password
$link = mysql_connect('lightning','bioskill','bioskill');

# Checking connection. If failed - print error message
if (!$link) die("connection error: ".mysql_error());

# Selecting the database
# [, $link] specifies what is the relevant connection (if several exist). 
mysql_select_db('BioEx3'[,$link]) 
or die("could not select db".mysql_error());


# Sending a query. $link specifies what is the relevant connection.

($result = "mysql_query("select * from snpNih limit 5"[,$link]))
	or die("query failed".mysql_error() );

# Printing the result.

print "<table>";
while ($line = mysql_fetch_array($result))
{	
    print "<tr><td>";
    foreach ($line as $col)
	{ print "$col"."</td><td>"; }
   print "</td></tr>";

}

Running External Programs

o Many things can be written in PHP, but sometimes there is a 
  need to run an external program. 
o This can be done in a similar way to perl, with backticks 
  operator, or with system() or exec() calls. 
o The program must be executed from a safe jailed 
  directory /cs/jailbird/home/.
# returns the command output
$tree = `tree`;
print $tree;


# Does the same but return only the last line of the output.
# $retval is the return value of the command

$tree = system('tree', $retval)
print $tree;



# exec returns the last line of the command output.
# $array argument is filled with the output, where each element is a row.

$output = exec('ls -l', $output_array);
foreach ($output_array as $line)
{
 print $line.'<br>';
}

The File System

As you could have guessed, all the commands required for 
traversing and changing the file system exists. 

file_system.php, see the  code


Sending an e-Mail


# mail(to, subject, message[, additional parameters])
# additional parameters are string headers.

$message_body = "this is the body";
mail('bioskill@cs.huji.ac.il','header',
$message_body, 'From: naomih@cs.huji.ac.il');


 mail.php