The TcpClient class wrappers the networking details for reading/writing to a network stream into a simple, easy-to-use class (much like .NET TcpClient). An example use, connecting to a POP mail server, is attached. Change the POP server details and username/password at the top of the file to test.
By : wmfwlr
<!-- EXAMPLE SCRIPT USING CLASS -->
<font face="verdana" size="2">
<?
include('class.TcpClient.php');
//** Displays the error message given if there is non-empty text.
function ShowError($errortext)
{
if(strlen($errortext) > 0)
print("<font color='red'>$errortext</font><br>");
}
//** the POP server address, user account, and password to use for
//** testing client application. NOTE: your POP user name is your
//** full email address, unless the server is otherwise configured.
$PopServer = "popserver.yourdomain.com";
$PopUser = "email@yourdomain.com";
$PopPassword = "yourpassword";
//** connect to the POP server given on 110, the standard POP port.
//** Change this if necessary.
$client = new TcpClient($PopServer, 110);
//** set the default read/write timeout to 2 seconds (2000 ms).
$client->Timeout = 2000;
//** you can set the default newline character(s) used when sending data.
$client->NewLine = "\r\n";
//** connect to server and get any error message (if available).
$client->Connect();
ShowError($client->GetError());
//** get the mailserver greeting (one line).
print("<b>" . $client->ReadLine() . "</b><br>");
ShowError($client->GetError());
//** send user login info to the server.
print($client->WriteLine("USER $PopUser") . " bytes written<br>");
ShowError($client->GetError());
//** get the mailserver USER response message.
print("<b>" . $client->ReadLine() . "</b><br>");
ShowError($client->GetError());
//** send user account password to the server.
print($client->WriteLine("PASS $PopPassword") . " bytes written<br>");
ShowError($client->GetError());
//** get the mailserver PASS response message, login success
print("<b>" . $client->ReadLine() . "</b><br>");
ShowError($client->GetError());
//**!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
//**!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
//**
//** Put any other commands for the POP server here!
//** Full command list @ http://www.ietf.org/rfc/rfc1939.txt
//**
//**!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
//**!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
//** notify the mail server connection is closing.
print($client->WriteLine("QUIT") . " bytes written<br>");
ShowError($client->GetError());
//** get the mailserver farewell message.
print("<b>" . $client->ReadLine() . "</b><br>");
ShowError($client->GetError());
$client->Close();
?>
</font>
<?
//-- CLASS FILE FOR TCP CLIENT --
//** ©William Fowler (wmfwlr@cogeco.ca)
//** DECEMBER 22/2003, Version 1.0
if(isset($GLOBALS["tcpclientclass_php"])) { return; } //** include once.
$GLOBALS["tcpclientclass_php"] = 1; //** file included.
//** error code indicating that no connection is available.
define("TcpClientNoConnection", 0);
//** the default number of milliseconds to wait before timing out.
define("TcpClientDefaultTimeout", 30000);
//** the minimum buffer size for the TCP client class.
define("TcpClientMinBufferSize", 256);
//** the default newline character(s) used.
define("TcpClientNewLine", "\r\n");
//**!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
//**TCP_CLIENT_CLASS_DEFINITION***********************************************
//** The TcpClient class encapsulates most networking communication details
//** into an easy-to-use wrapper. Connections are not persistant.
class TcpClient
{
//** (Integer) the internal underlying socket identifier.
var $Socket = TcpClientNoConnection;
//** (String) the name/IP of the remote host
var $Host;
//** (Integer) the port number to connect to remote host.
var $Port = 0;
//** (String) the last error that occurred (NULL if no error).
var $LastError = null;
//** (String) the newline character to be used when sending data.
var $NewLine = TcpClientNewLine;
//** (Integer) the size of the buffer used to receive data.
var $ReceiveBufferSize = TcpClientMinBufferSize;
//** (Integer) the number of milliseconds to wait before aborting a connect,
//** read, or write operation for the client.
var $Timeout = TcpClientDefaultTimeout;
//** creates a new TcpClient instance based on the hostname and port given.
function TcpClient($remoteHost=null, $portNum=0)
{
$this->Host = strval($remoteHost);
$this->Port = intval(max(0, $portNum)); //** ensure port >= than zero.
}
//** Returns: Boolean
//** Determine whether or not a connection to the remote host has been
//** established.
function isOpen()
{
return ($this->Socket ? true : false);
}
//** Returns: String
//** Get the last recorded error that occurred. If no error previously
//** occurred NULL is returned. The last error is cleared.
function GetError()
{
$theerror = $this->LastError;
$this->ClearError();
return $theerror;
}
//** Returns: None
//** Clear the last error stored for this client.
function ClearError()
{
$this->LastError = null;
}
//** Returns: Boolean
//** Attemept to connect to the client remote host on the port number given.
//** If no host is available FALSE is returned and no connection is made.
//** If FALSE is returned the last error is available from the 'GetError()'
//** method.
function Connect()
{
$this->ClearError(); //** clear any existing error messages.
//** no host name/IP has been set for this client, no connection can be made.
//** Store the appropriate error.
if(strlen(trim($this->Host)) == 0)
{
$this->LastError = "No remote host was provided";
return false;
}
//** attempt to connect to the host on the port given. Record any error number
//** and error message generated.
$errorNum = 0;
$this->Socket = fsockopen($this->Host, $this->Port, &$errorNum,
&$this->LastError, ($this->Timeout / 1000));
//** if there is no error given and the socket is valid connection is okay.
return ($this->isOpen() && strlen(trim($this->LastError)) == 0);
}
//** Returns: Boolean
//** Attempt to close the open client connection.
function Close()
{
//** no open cobnnection is available. Set error appropriately.
if(!$this->isOpen())
$this->LastError = "No connection available to close";
//** an open connection is available to close. Close underlying socket.
else
{
fclose($this->Socket); //** clsoe the connection.
$this->Socket = TcpClientNoConnection; //** no connection now.
}
return !$this->isOpen(); //** return the close operation success.
}
//** Returns: Integer
//** Attempt to write the data given to the underlying socket. The number of
//** bytes successfully written to the stream is returned. If no connection
//** is available 0 is returned, as no bytes were written.
function Write($data=null)
{
//** no connection is available, zero bytes can be sent.
if(!$this->isOpen())
{
$this->LastError = "No connection available for writing";
return 0;
}
$data = strval($data); //** ensure that data is available.
if(strlen($data) == 0) //** no data to be sent.
return 0; //** zero bytes were sent.
else //** connection and data, set timeout and send.
{
$this->_SetTimeout(); //** set timeout.
return fwrite($this->Socket, $data, strlen($data)); //** write data.
}
}
//** Returns: Integer
//** Attempt to write the data given to the underlying socket, followed by a
//** newline. The newline is defined by the '$this->NewLine' property. The
//** number of bytes actually written is returned.
function WriteLine($data=null)
{
return $this->Write($data . $this->NewLine);
}
//** Returns: String
//** Attempt to read the number of bytes given (or one by default) from the
//** connection. If no connection is available, the length given is zero or
//** negative, or an error occurs NULL is returned.
function Read($length=1)
{
if(intval($length) <= 0)
{
$this->LastError = "Cannot read zero or less bytes";
return null;
}
//** no connection is available to read from, no data can be read.
else if(!$this->isOpen())
{
$this->LastError = "No connection available for reading";
return null;
}
else //** a valid connection identifier is available.
{
$this->_SetTimeout(); //** ensure timeout is set.
return fread($this->Socket, $length); //** attempt to read n-bytes.
}
}
//** Returns: String
//** Attempt to read one full line from the underlying stream. If no
//** connection is available NULL is returned. Any newline characters
//** are included in the string returned.
function ReadLine()
{
//** no connection is available to read from, no data can be read.
if(!$this->isOpen())
{
$this->LastError = "No connection available for reading";
return null;
}
//** continue to read in data until a line ends with the newline character(s).
//** This is safe as the 'fgets()' function will not read past a newline
//** character. Ensure that the read buffer is at least the minumum size. If
//** one iteration is complete and no data was read in the socket blocking
//** expired. Stop reading at that point.
$streamdata = ""; //** no data to start with.
$sockethasexpired = false; //** initially no timeout experienced.
while(!$this->_EndsWithNewLine($streamdata) && !$sockethasexpired)
{
$this->_SetTimeout(); //** ensure socket timeout is set.
$streamdata .= fgets($this->Socket, max(TcpClientMinBufferSize,
$this->ReceiveBufferSize));
//** if ever at the point where reading has occurred and no data is available
//** a socket timeout has occurred. Exit the loop and set the error.
if(strlen($streamdata) == 0)
{
$sockethasexpired = true;
$this->LastError = "The read took longer than $this->Timeout ms";
}
}
return $streamdata; //** return the data received, including newline.
}
//** Returns: Boolean
//** Determine whether or not the string given ends with a newline character.
//** If no data is given FALSE is returned.
function _EndsWithNewLine($data=null)
{
$data = strval($data); //** ensure that data is a string.
if(strlen($data) == 0) //** no date given to test.
return false; //** does not end with newline.
//** get the position of the last newline character. If the value returned
//** is not numeric it is a boolean, indicating no match. Considered to end
//** with newline if it ends with either a '\n' or '\r' character.
$creturnpos = strrpos($data, "\r"); //** position of '\n'.
$newlinepos = strrpos($data, "\n"); //** position of '\r'.
return (is_int($newlinepos) || is_int($creturnpos));
}
//** Returns: None
//** Set the underlying socket timeout to the 'Timeout' value for this
//** instance. If not connected nothing is done.
function _SetTimeout()
{
//** if a connection is available set the socket timeout. Get the number of
//** seconds and microseconds form the instance 'Timeout' property.
if($this->isOpen())
{
stream_set_timeout($this->Socket, intval($this->Timeout / 1000),
intval(($this->Timeout % 1000) * 1000));
}
}
}
?>
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