ZCOM C I/F Library Routines
ZREAD (3X)
rlen (Return Actual data length. NULL may be specified if the caller does
Param) not require the returned message length. Note that rlen may exceed len. This indicates the received data is truncated to just fill up ibuf.
rstat |
| Return status. | ||
(Return | 0 | - no error | ||
Param) | ||||
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| +ve | - terminal error status | |
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| It is meaningful only if the returned message is a response or | ||
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| terminal message. For other message types, it is always | ||
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| returned with zero. NULL may be specified if the caller does | ||
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| not require this return status. | ||
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| The return status rstat and the request code | ||
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| by calling zcomstatus(3X). | ||
NOTES | 1. If zsend(3X) was used to send data using modes 1, 2, 5, or 7, then the | |||
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| input ZLU queue may contain response status messages. If the sent | ||
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| message could not be delivered by the driver (e.g., data corruption in | ||
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| the host system), an error response is returned to the sender’s | ||
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| primary ZLU. When such an error response is picked up by zread, the | ||
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| function returns with zero (indicating no problem in reading the | ||
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| input ZLU), the returned message type is set (e.g., | ||
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| ZCOM_MSTYPE_RSLT) and the return status will carry a negative | ||
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| ZCOM error code. If the message could not be delivered by the | ||
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| interface (e.g., a problem with the terminal line), the returned | ||
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| response will have a positive ZCOM status code indicating the | ||
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| problem. |
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2.If the received message (or response) is from a terminal, the request code is returned in
Chapter 4 | 299 |