(PHP 4, PHP 5)
fsockopen — Open Internet or Unix domain socket connection
$hostname
[, int $port = -1
[, int &$errno
[, string &$errstr
[, float $timeout = ini_get("default_socket_timeout")
]]]] )
Initiates a socket connection to the resource specified by
hostname.
PHP supports targets in the Internet and Unix domains as described in 所支持的套接字传输器（Socket Transports）列表. 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().
The function stream_socket_client() is similar but provides a richer set of options, including non-blocking connection and the ability to provide a stream context.
hostname
If OpenSSL support is
installed, 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
timeoutparameter to fsockopen() only applies while connecting the socket.
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
Throws E_WARNING if hostname is
not a valid domain.
| 版本 | 说明 |
|---|---|
| 4.3.0 |
Added support for the timeout parameter on
win32.
|
| 4.3.0 | SSL and TLS over TCP/IP support was added. |
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);
}
?>
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);
}
?>
Note:
Depending on the environment, the Unix domain or the optional connect timeout may not be available.
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: 当指定数值型的 IPv6 地址（例如 fe80::1）时必须用方括号将 IP 围起来——例如， tcp://[fe80::1]:80。