Networking Functions-PHP

When using the PHP binaries for Windows that are available from http://php.net/, the getprotobyname(), getprotobynumber(), getservbyport(), and getservbyname() may not function as anticipated under Windows 2000.

DNS resource records:

• checkdnsrr()
• getmxrr()

Domain name/IP address lookups and conversions:

• gethostbyaddr()
• gethostbyname()
• gethostbynamel()
• ip2long()
• long2ip()

Internet protocol and service information:

• getprotobynumber()
• getservbyname()
• getprotobyname()
• getservbyport()

PHP 3 debugger (warning: very broken!):

• debugger_off()
• debugger_on()

Sockets:

• fsockopen()
• pfsockopen()
• socket_get_status()
• socket_set_blocking()
• socket_set_timeout()
  
  

  gethostbyaddr() 
  gethostbyname() 
  gethostbynamel() 
  getmxrr() 

  Example:

  Check whether a given domain name has an MX resource record

  <?php 
  $url = "http://www.php.net/"; 
  $component = parse_url ($url); 
  checkdnsrr ($component['host'], 'MX') 
      or die ('No MX record exists for <i>$component[host]</i>. 
          Did you enter the URL correctly?'); 
  echo "MX record found for <i>$component[host]</i>"; 
  ?> 

  

  fsockopen

  mixed fsockopen(string host, int port, [reference error_number], 
   [reference error_string], [double timeout]) 

  host	Hostname or IP address
  port	Port number
  error_number	Reference to a variable that will store the system-level error number if the function fails
  error_string	Reference to a variable that will store the system-level error message if the function fails
  timeout	Number of seconds before the connect system call times out

  Opens a connection to a socket.
  Returns:
  File pointer identifying the open socket; FALSE on failure
  Description:
  fsockopen() attempts to open a network socket connection to the specified host and port. TCP connections are assumed by default, but UDP connections can be specified by placing udp:// at the start of the host .
  
  
  There are three optional arguments: error_number , error_string , and timeout . Both the error_number and error_string arguments must be passed as references, as in &$error_number and &$error_string. If an error occurs, these variables will contain an error code and a message. If the error number is 0, this is usually due to a problem that occurs before the socket initializes, such as an incorrect hostname.
  
  
  The timeout argument should contain the maximum number of seconds to wait for a connection before timing out.
  
  

open a socket

<?php 
$host = 'www.abcxyz.com'; 
$port = 80; 

$fp = fsockopen($host, $port, &$err_no, &$err_msg, 10) 
    or die ("Could not open a socket connection to host 
         <i>$host</i> on port <i>$port</i>. 
         The error message returned was '<i>$err_msg</i>'."); 
echo "A socket connection to host <i>$host</i> on port 
   <i>$port</i> was successfully opened." 
?>