Function for receiving an UDP message from a server.
The station (nPort and nAddr) was previously specified via an udp_open_client().
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i32 udp_recv (i32 idx, buff, i32 buffLen)
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Number of the UDP communication handler
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Generic buffer intended to contain the received data packet.
It can be a string variable, struct_p (packed structure), or an array of struct_p. In the case of struct_p, the variable must be declared global
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Maximum number of bytes to receive
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Returns:
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>= 0
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Operation performed successfully. The number of characters received is returned
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-1
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Illegal idx
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-2
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Socket not open
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-3
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Socket open as server and not as client
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-1000 -:- -2000
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Error code of the S.O. function recv(), with offset 1000
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To see some returned errors more specifically, see Returned Errors Table
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Rule, Task
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The udp_recv() can only be used for client communications
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For a concrete example see in RDE environment: Workspace -> Specials -> Examples Library.
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-1004
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[EINTR] Reading was interrupted before any data was received
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-1009
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[EBADF] Id invalid
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-1011
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[EAGAIN] Retry. Socket was non-blocking and reception would block execution, or a timeout on reception was imposed and that timeout expired before any data was received
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-1014
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[EFAULT] Buffer pointer points to a memory area outside the process space
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-1022
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[EINVAL] The total I/O length is greater than the maximum that can be represented by the returned type
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-1088
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[ENOTSOCK] Invalid id, does not refer to a socket
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-1105
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[ENOBUFS] The message was not sent because it would have exceeded the maximum buffer size
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-1107
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[ENOTCONN] The connection has not yet been created
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-1122
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[EMSGSIZE] Message too long
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NOTE: For the complete table of error codes see Error codes functions paying attention at the offset.
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