fsockopen
(PHP 3, PHP 4, PHP 5)
fsockopen -- Open Internet or Unix domain socket connection
Description
resource
fsockopen ( string hostname [, int port [, int &errno [, string &errstr [, float timeout]]]] )
Initiates a socket connection to the resource specified by
hostname.
PHP supports targets in the Internet and Unix domains as described in
Appendix Q. A list of supported transports can also be
retrieved using stream_get_transports().
The socket will by default be opened in blocking mode. You can
switch it to non-blocking mode by using
stream_set_blocking().
Parameters
hostname
If you have compiled in OpenSSL support, you may prefix the
hostname with either ssl://
or tls:// to use an SSL or TLS client connection
over TCP/IP to connect to the remote host.
port
The port number.
errno
If provided, holds the system level error number that occurred in the
system-level connect() call.
If the value returned in errno is
0 and the function returned FALSE, it is an
indication that the error occurred before the
connect() call. This is most likely due to a
problem initializing the socket.
errstr
The error message as a string.
timeout
The connection timeout, in seconds.
Note:
If you need to set a timeout for reading/writing data over the
socket, use stream_set_timeout(), as the
timeout parameter to
fsockopen() only applies while connecting the
socket.
Return Values
fsockopen() returns a file pointer which may be used
together with the other file functions (such as
fgets(), fgetss(),
fwrite(), fclose(), and
feof()). If the call fails, it will return FALSE
Examples
Example 1. fsockopen() Example
<?php
$fp = fsockopen("www.example.com", 80, $errno, $errstr, 30);
if (!$fp) {
echo "$errstr ($errno)<br />\n";
} else {
$out = "GET / HTTP/1.1\r\n";
$out .= "Host: www.example.com\r\n";
$out .= "Connection: Close\r\n\r\n";
fwrite($fp, $out);
while (!feof($fp)) {
echo fgets($fp, 128);
}
fclose($fp);
}
?>
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Example 2. Using UDP connection
The example below shows how to retrieve the day and time from the UDP
service "daytime" (port 13) in your own machine.
<?php
$fp = fsockopen("udp://127.0.0.1", 13, $errno, $errstr);
if (!$fp) {
echo "ERROR: $errno - $errstr<br />\n";
} else {
fwrite($fp, "\n");
echo fread($fp, 26);
fclose($fp);
}
?>
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Notes
Note:
Depending on the environment, the Unix domain or the optional
connect timeout may not be available.
| Warning |
UDP sockets will sometimes appear to have opened without an error,
even if the remote host is unreachable. The error will only
become apparent when you read or write data to/from the socket.
The reason for this is because UDP is a "connectionless" protocol,
which means that the operating system does not try to establish
a link for the socket until it actually needs to send or receive data.
|
Note: When specifying a numerical IPv6 address
(e.g. fe80::1) you must enclose the IP in square brackets. For example,
tcp://[fe80::1]:80.
