预定义常量

下列常量由此扩展定义，且仅在此扩展编译入 PHP 或在运行时动态载入时可用。

Constant	Description
STREAM_FILTER_READ	Used with stream_filter_append() and stream_filter_prepend() to indicate that the specified filter should only be applied when reading
STREAM_FILTER_WRITE	Used with stream_filter_append() and stream_filter_prepend() to indicate that the specified filter should only be applied when writing
STREAM_FILTER_ALL	This constant is equivalent to STREAM_FILTER_READ | STREAM_FILTER_WRITE
PSFS_PASS_ON	Return Code indicating that the userspace filter returned buckets in $out.
PSFS_FEED_ME	Return Code indicating that the userspace filter did not return buckets in $out (i.e. No data available).
PSFS_ERR_FATAL	Return Code indicating that the userspace filter encountered an unrecoverable error (i.e. Invalid data received).
PSFS_FLAG_NORMAL	Regular read/write.
PSFS_FLAG_FLUSH_INC	An incremental flush.
PSFS_FLAG_FLUSH_CLOSE	Final flush prior to closing.
STREAM_USE_PATH	Flag indicating if the stream used the include path.
STREAM_REPORT_ERRORS	Flag indicating if the wrapper is responsible for raising errors using trigger_error() during opening of the stream. If this flag is not set, you should not raise any errors.
STREAM_CLIENT_ASYNC_CONNECT	Open client socket asynchronously. This option must be used together with the STREAM_CLIENT_CONNECT flag. Used with stream_socket_client().
STREAM_CLIENT_CONNECT	Open client socket connection. Client sockets should always include this flag. Used with stream_socket_client().
STREAM_CLIENT_PERSISTENT	Client socket opened with stream_socket_client() should remain persistent between page loads.
STREAM_SERVER_BIND	Tells a stream created with stream_socket_server() to bind to the specified target. Server sockets should always include this flag.
STREAM_SERVER_LISTEN	Tells a stream created with stream_socket_server() and bound using the STREAM_SERVER_BIND flag to start listening on the socket. Connection-orientated transports (such as TCP) must use this flag, otherwise the server socket will not be enabled. Using this flag for connect-less transports (such as UDP) is an error.
STREAM_NOTIFY_RESOLVE	A remote address required for this stream has been resolved, or the resolution failed. See severity for an indication of which happened.
STREAM_NOTIFY_CONNECT	A connection with an external resource has been established.
STREAM_NOTIFY_AUTH_REQUIRED	Additional authorization is required to access the specified resource. Typical issued with severity level of STREAM_NOTIFY_SEVERITY_ERR.
STREAM_NOTIFY_MIME_TYPE_IS	The mime-type of resource has been identified, refer to message for a description of the discovered type.
STREAM_NOTIFY_FILE_SIZE_IS	The size of the resource has been discovered.
STREAM_NOTIFY_REDIRECTED	The external resource has redirected the stream to an alternate location. Refer to message.
STREAM_NOTIFY_PROGRESS	Indicates current progress of the stream transfer in bytes_transferred and possibly bytes_max as well.
STREAM_NOTIFY_COMPLETED	There is no more data available on the stream.
STREAM_NOTIFY_FAILURE	A generic error occurred on the stream, consult message and message_code for details.
STREAM_NOTIFY_AUTH_RESULT	Authorization has been completed (with or without success).
STREAM_NOTIFY_SEVERITY_INFO	Normal, non-error related, notification.
STREAM_NOTIFY_SEVERITY_WARN	Non critical error condition. Processing may continue.
STREAM_NOTIFY_SEVERITY_ERR	A critical error occurred. Processing cannot continue.
STREAM_IPPROTO_ICMP +	Provides a ICMP socket.
STREAM_IPPROTO_IP +	Provides a IP socket.
STREAM_IPPROTO_RAW +	Provides a RAW socket.
STREAM_IPPROTO_TCP +	Provides a TCP socket.
STREAM_IPPROTO_UDP +	Provides a UDP socket.
STREAM_PF_INET +	Internet Protocol Version 4 (IPv4).
STREAM_PF_INET6 +	Internet Protocol Version 6 (IPv6).
STREAM_PF_UNIX +	Unix system internal protocols.
STREAM_SOCK_DGRAM +	Provides datagrams, which are connectionless messages (UDP, for example).
STREAM_SOCK_RAW +	Provides a raw socket, which provides access to internal network protocols and interfaces. Usually this type of socket is just available to the root user.
STREAM_SOCK_RDM +	Provides a RDM (Reliably-delivered messages) socket.
STREAM_SOCK_SEQPACKET +	Provides a sequenced packet stream socket.
STREAM_SOCK_STREAM +	Provides sequenced, two-way byte streams with a transmission mechanism for out-of-band data (TCP, for example).
STREAM_SHUT_RD	Used with stream_socket_shutdown() to disable further receptions. Added in PHP 5.2.1.
STREAM_SHUT_WR	Used with stream_socket_shutdown() to disable further transmissions. Added in PHP 5.2.1.
STREAM_SHUT_RDWR	Used with stream_socket_shutdown() to disable further receptions and transmissions. Added in PHP 5.2.1.
STREAM_CAST_FOR_SELECT	Stream casting, for when stream_select() is calling stream_cast().
STREAM_CAST_AS_STREAM	Stream casting, when stream_cast() is called otherwise (see above).
STREAM_META_TOUCH	Used with stream_metadata(), to specify touch() call.
STREAM_META_OWNER	Used with stream_metadata(), to specify chown() call.
STREAM_META_OWNER_NAME	Used with stream_metadata(), to specify chown() call.
STREAM_META_GROUP	Used with stream_metadata(), to specify chgrp() call.
STREAM_META_GROUP_NAME	Used with stream_metadata(), to specify chgrp() call.
STREAM_META_ACCESS	Used with stream_metadata(), to specify chmod() call.

Note: The constants marked with + are available since PHP 5.1.0 and are meant to be used with stream_socket_pair(). Please note that some of these constants might not be available in your system.

Note: The STREAM_META_* constants are available since PHP 5.4.0 and are meant to be used with stream_metadata().