Thread: Copy int array into another int array

  1. #1
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    Copy int array into another int array

    H,

    I need to Copy int array elements into another int array. Here is the function.

    Code:
    uint8_t SPI_Exchange8bitBuffer(uint8_t *dataIn, uint8_t bufLen, uint8_t *dataOut)
    {
        uint8_t bytesWritten = 0;
        extern volatile uint8_t buf[];
        if(dataOut != NULL)
                {
                    while(bytesWritten < bufLen )
                    {
                        dataOut[bytesWritten] = Send_data(dataIn);
    
    
                        bytesWritten++;
                    }
                    strncpy(buf, dataOut, bytesWritten);  //Is this correct?
                }
    }
    Will buf contain all received elements of dataOut? Is there any issue as buf is an int array and dataOut is a pointer to int array?

    --David

  2. #2
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    Use memcpy, not strncpy. strncpy will copy at most the requested number of bytes but will stop early when it copies a zero byte. memcpy will always copy the requested number of bytes, even if they're all zeroes.

    In general, your code looks strange. What does Send_data do? If it only sends one byte then you're passing a pointer to the same byte every loop iteration. If it passes the whole dataIn array then it is doing it multiple times. And what is the return value?

  3. #3
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    Hi Algorism...Thanks. I will use memcpy. I have not given full detail actually. uint8_t SPI_Exchange8bitBuffer will be called more than once from main function. Send_data does some operation on incoming dataIn every time and get dataOut. Incoming data dataIn will be like 0x11, 0x12, 0x13, 0x14. Same way dataOut will be like 0x66, 0x77, 0x88, 0x99. Now this dataOut I wanted to copy into separate uint8_t buf[] for further use. Let me know if it is fine.

  4. #4
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    Quote Originally Posted by davidmeetsall View Post
    Let me know if it is fine.
    I can't follow that so I really don't know. It obviously depends on the details of the rest of your code.

    Does it compile?
    Does it run?
    Does it do what you expect?

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