Using fread to retrieve data from fsockopen connection... please help!

jimmyjoebob · Apr 29, 2002

I'm having an issue that I hope someone will be able to lend a hand with. In the example below, we have a Unix server running Linux and PHP. The PHP script will attempt to open a socket communication with a Windows 2000 server using fsockopen. Basically emulating a telnet session. It will send a command to the Win2k server using fputs, then listen for the results using fread.

The problem is that it doesn't work all the time. I think it has to do with some control characters coming back that's throwing it off, but I'm not sure.

If I send: "create account (username) (password)"
The account is created!, but it will stall out on the fread!

If I send: "show account..."
It will send back the results as I need.

Doesn anyone have any feedback they'd like to offer?

Thanks, in advance, for your help!

============ START CODE SAMPLE ============
<?
function sendToHost($host,$port,$data)
{
$fp = fsockopen($host,$port,$errno,$errstr);
if (!$fp) {
return "Error - $errstr ($errno) \n";
} else {
fputs($fp, $data . "\r\n\r\n&quot

;
$buf = fread($fp,128);
//while (!feof($fp)) {
// $buf .= fread($fp,128);
//}
fclose($fp);
return $buf;
}
}

// Set variables for communication
$host = "xxx.xxx.xxx.xxx";
$port = 9999;
//$data = "create account (username) (password)";
$data = "show account (username)";
//
?>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>Test PHP sockets</title>
</head>
<body>
This server: <?= $HTTP_SERVER_VARS['SERVER_NAME']; ?> 
This IP: <?= gethostbyname($HTTP_SERVER_VARS['SERVER_NAME']); ?>
<hr>
Communication with <?= $host; ?> on port <?= $port ?> 
Data sent: <?= $data; ?> 
Data received:
<hr>
<?= nl2br (sendToHost($host,$port,$data)); ?>
</body>
</html>
============ END CODE SAMPLE ============

jimmyjoebob · May 1, 2002

For those interested, this is what I had to do to the sentToHost() function in order to get it to work properly. (see sample below)

I'm not sure what the problem was with detecting the end-of-file, so I had to write a work-around. If ANYONE has any feedback that could help me "correctly" solve the problem, I'd be eternally grateful. It's not a big issue now though, since the work-around is functioning within nominal parameters. ;-)

Thanks.. and Enjoy!

============ START CODE SAMPLE ============
<?
// sendToHost : This function is used to send/receive data to a remote server
// $host : fully qualified domain name or an IP address
// $port : port on the host to communicate with
// $data : the data, or command, sent to the host
function sendToHost($host,$port,$data)
{
// Open domain socket connection
$fp = fsockopen($host,$port,$errno,$errstr);
// If the open was unsuccessful, return an error
if (!$fp) {
return "Error - $errstr ($errno) \n";
// If the open was successful, process the command
} else {
// Send the command to the server
fputs($fp, $data . "\r\n\r\n&quot

;
// Receive the feedback from server
//
// Example data returned from the server
// -------------------------------------
// > create automated (username) (password)
// Created account 46.
// 46 13429U User4658856894
// >
// -------------------------------------
// The results will be contained between two ">" characters (or telnet prompts)
// For some reason, fread() isn't trapping for end-of-file! So.. we need
// to stop the feedback at the 2nd ">" character.
//
// $prompt_count : number of ">" characters encountered.
// $pos : character pointer - keeps track of buffer position.
// $char_buf : temporary buffer to hold last character received
// $all_buf : cumulative buffer of all characters received
//
// Read up to 300 characters of feedback from the server
// Stop when the 2nd ">" character is detected
$prompt_count = 0;
for ( $pos = 0; $pos < 300; ++$pos )
{
$char_buf = fread($fp,1);
$all_buf .= $char_buf;
if ($char_buf == ">&quot

{ $prompt_count++; }
if ($prompt_count > 1) { $pos = 300; }
}
// Close domain socket connection
fclose($fp);
// Return the buffer
return $all_buf;
}
}
?>
============ END CODE SAMPLE ============

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Using fread to retrieve data from fsockopen connection... please help!

jimmyjoebob

Programmer

jimmyjoebob

Programmer

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