The GetNamedPipeHandleState function retrieves information about a specified named pipe. The information returned can vary during the lifetime of an instance of the named pipe.
BOOL GetNamedPipeHandleState(
| HANDLE hNamedPipe, | // handle of named pipe |
| LPDWORD lpState, | // address of flags indicating pipe state |
| LPDWORD lpCurInstances, | // address of number of current pipe instances |
| LPDWORD lpMaxCollectionCount, | // address of max. bytes before remote transmission |
| LPDWORD lpCollectDataTimeout, | // address of max. time before remote transmission |
| LPTSTR lpUserName, | // address of user name of client process |
| DWORD nMaxUserNameSize | // size, in characters, of user name buffer |
| ); |
Parameters
hNamedPipe
Identifies the named pipe for which information is wanted. The handle must have GENERIC_READ access to the named pipe.
lpState
Points to a 32-bit variable that indicates the current state of the handle. This parameter can be NULL if this information is not needed. Either or both of the following values can be specified:
| Value | Meaning |
| PIPE_NOWAIT | The pipe handle is in nonblocking mode. If this flag is not specified, the pipe handle is in blocking mode. |
| PIPE_READMODE_MESSAGE | The pipe handle is in message-read mode. If this flag is not specified, the pipe handle is in byte-read mode. |
lpCurInstances
Points to a 32-bit variable that receives the number of current pipe instances. This parameter can be NULL if this information is not required.
lpMaxCollectionCount
Points to a 32-bit variable that receives the maximum number of bytes to be collected on the client's computer before transmission to the server. This parameter must be NULL if the specified pipe handle is to the server end of a named pipe or if client and server processes are on the same computer. This parameter can be NULL if this information is not required.
lpCollectDataTimeout
Points to a 32-bit variable that receives the maximum time, in milliseconds, that can pass before a remote named pipe transfers information over the network. This parameter must be NULL if the specified pipe handle is to the server end of a named pipe or if client and server processes are on the same computer. This parameter can be NULL if this information is not required.
lpUserName
Points to a buffer that receives the null-terminated string containing the user name string of the client application. This parameter must be NULL if the specified pipe handle is to the client end of a named pipe. This parameter can be NULL if this information is not required.
nMaxUserNameSize
Specifies the size, in characters, of the buffer specified by the lpUserName parameter. This parameter is ignored if lpUserName is NULL.
Return Values
If the function succeeds, the return value is nonzero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.
Remarks
The GetNamedPipeHandleState function returns successfully even if all of the pointers passed to it are NULL.
To set the pipe handle state, use the SetNamedPipeHandleState function.
See Also