The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.
| 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().