PRB: Named Pipe Write() Limited to 64K

Last reviewed: December 16, 1996
Article ID: Q119218

The information in this article applies to:

Microsoft Win32 Application Programming Interface (API) included with:
```
    - Microsoft Windows NT versions 3.1, 3.5, 3.51 and 4.0
```

SYMPTOMS

WriteFile() returns FALSE and GetLastError() returns ERROR_MORE_DATA when WriteFile() writes to a message-mode named pipe using a buffer greater than 64K.

CAUSE

There is a 64K limit on named pipe writes.

RESOLUTION

The error is different from ERROR_MORE_DATA on the reader side, where bytes have already been read and the operation should be retried for the remaining message. The real error is STATUS_BUFFER_OVERFLOW. No data is transmitted; therefore, the write operation must be retried using a smaller buffer.

KBCategory: kbprg kbprb
KBSubcategory: BseIpc
Additional reference words: 3.10 3.50 3.51 4.00

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Last reviewed: December 16, 1996
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