Php/docs/function.stream-socket-client
stream_socket_client
(PHP 5, PHP 7)
stream_socket_client — Open Internet or Unix domain socket connection
说明
stream_socket_client
( string $remote_socket
[, int &$errno
[, string &$errstr
[, float $timeout
= ini_get("default_socket_timeout")
[, int $flags
= STREAM_CLIENT_CONNECT
[, resource $context
]]]]] ) : resource
Initiates a stream or datagram connection to the destination specified
by remote_socket
. The type of socket created
is determined by the transport specified using standard URL formatting:
transport://target
. For Internet Domain sockets
(AF_INET) such as TCP and UDP, the target
portion
of the remote_socket
parameter should consist of
a hostname or IP address followed by a colon and a port number. For Unix
domain sockets, the target
portion should point
to the socket file on the filesystem.
Note:
The stream will by default be opened in blocking mode. You can switch it to non-blocking mode by using stream_set_blocking().
参数
remote_socket
Address to the socket to connect to.
errno
Will be set to the system level error number if connection fails.
errstr
Will be set to the system level error message if the connection fails.
timeout
Number of seconds until the
connect()
system call should timeout.Note:
This parameter only applies when not making asynchronous connection attempts.
Note:
To set a timeout for reading/writing data over the socket, use the stream_set_timeout(), as the
timeout
only applies while making connecting the socket.flags
Bitmask field which may be set to any combination of connection flags. Currently the select of connection flags is limited to
STREAM_CLIENT_CONNECT
(default),STREAM_CLIENT_ASYNC_CONNECT
andSTREAM_CLIENT_PERSISTENT
.context
A valid context resource created with stream_context_create().
返回值
On success a stream resource is returned which may
be used together with the other file functions (such as
fgets(), fgetss(),
fwrite(), fclose(), and
feof()), false
on failure.
错误/异常
On failure the errno
and
errstr
arguments will be populated with the actual
system level error 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. Note that
the errno
and
errstr
arguments will always be passed by
reference.
范例
Example #1 stream_socket_client() example
<?php$fp = stream_socket_client("tcp://www.example.com:80", $errno, $errstr, 30);if (!$fp) { echo "$errstr ($errno)<br />\n";} else { fwrite($fp, "GET / HTTP/1.0\r\nHost: www.example.com\r\nAccept: */*\r\n\r\n"); while (!feof($fp)) { echo fgets($fp, 1024); } fclose($fp);}?>
Example #2 Using UDP connection
Retrieving the day and time from the UDP service "daytime" (port 13) on localhost.
<?php$fp = stream_socket_client("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);}?>
注释
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:
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
。
Note:
Depending on the environment, the Unix domain or the optional connect timeout may not be available. A list of available transports can be retrieved using stream_get_transports(). See 所支持的套接字传输器(Socket Transports)列表 for a list of built in transports.
参见
- stream_socket_server() - Create an Internet or Unix domain server socket
- stream_set_blocking() - 为资源流设置阻塞或者阻塞模式
- stream_set_timeout() - Set timeout period on a stream
- stream_select() - Runs the equivalent of the select() system call on the given arrays of streams with a timeout specified by tv_sec and tv_usec
- fgets() - 从文件指针中读取一行
- fgetss() - 从文件指针中读取一行并过滤掉 HTML 标记
- fwrite() - 写入文件(可安全用于二进制文件)
- fclose() - 关闭一个已打开的文件指针
- feof() - 测试文件指针是否到了文件结束的位置
- cURL 函数