fsockopen
fsockopen
(PHP 4, PHP 5, PHP 7)
fsockopen — Open Internet or Unix domain socket connection
Description
resource fsockopen ( string $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 List of Supported Socket Transports. 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.
Parameters
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. This can be omitted and skipped with -1 for transports that do not use ports, such as unix://.
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 atimeoutfor reading/writing data over the socket, use stream_set_timeout(), as thetimeoutparameter tofsockopen()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
Errors/Exceptions
Throws E_WARNING if hostname is not a valid domain.
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
}
?>
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
}
?>
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.
See Also
- pfsockopen() - Open persistent Internet or Unix domain socket connection
- stream_socket_client() - Open Internet or Unix domain socket connection
- stream_set_blocking() - Set blocking/non-blocking mode on a stream
- stream_set_timeout() - Set timeout period on a stream
- fgets() - Gets line from file pointer
- fgetss() - Gets line from file pointer and strip HTML tags
- fwrite() - Binary-safe file write
- fclose() - Closes an open file pointer
- feof() - Tests for end-of-file on a file pointer
- socket_connect() - Initiates a connection on a socket
- The Curl extension
← dns_get_record
gethostbyaddr →
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Licensed under the Creative Commons Attribution License v3.0 or later.
