PeekNamedPipe

The PeekNamedPipe function copies data from a named or anonymous pipe into a buffer without removing it from the pipe. It also returns information about data in the pipe.

Parameters

hPipe

Specifies a handle to the named pipe. The handle must have GENERIC_READ access to the named pipe.

lpvBuffer

Points to a buffer for data read from the pipe. This parameter can be NULL if no data is to be read.

cbBuffer

Specifies the size in bytes of the buffer at lpvBuffer. This parameter is ignored if lpvBuffer is NULL.

lpcbRead

Points to a variable to be set to the number of bytes read from the pipe. This parameter can be NULL if no data is to be read.

lpcbAvail

Points to a variable to be set to the total number of bytes available to be read from the pipe. This parameter can be NULL if this information is not required.

lpcbMessage

Points to a variable to be set to the number of bytes remaining in this message. This will be zero for byte-mode pipes. This parameter can be NULL if this information is not required.

Return Value

The return value is TRUE if the function was successful, or FALSE if an error occurred. Use the GetLastError function to obtain extended error information.

Comments

The results of the PeekNamedPipe function are similar to calling ReadFile on the pipe, except more information is returned, the function never blocks and a partial message can be returned if the pipe handle is reading in message mode.

A partial message peeked on a message mode pipe will return TRUE.

This function works with named pipes (pipes created by the CreateNamedPipe function) or anonymous pipes (pipes created by the CreatePipe function).

See Also

CreateNamedPipe, CreatePipe, ReadFile, WriteFile