Simple pointer question

This is a discussion on Simple pointer question within the C Programming forums, part of the General Programming Boards category; Hi all. I am receiving serial data and placing it into a buffer. In main I am using a pointer ...

  1. #1
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    Apr 2006
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    Post Simple pointer question

    Hi all.

    I am receiving serial data and placing it into a buffer.
    In main I am using a pointer to view the elements of the buffer.
    Code:
    	        volatile char *pointer;	
                    pointer = pc_rx_buffer;
    I work my way through the buffer using
    Code:
                    pointer++;
    If the buffer created is,
    Code:
    	   
                    pc_rx_buffer[PC_Rx_BUFFER_SIZE])
    What is the correct way to test whether my pointer is at the last element of my buffer, so that I can reset my pointer to the beginning of my buffer?

    Im sure this is quite simple, but I'm through with scratching my head about this so I thought i would just ask.

    Thanks

  2. #2
    Just Lurking Dave_Sinkula's Avatar
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    One way:
    Code:
          if ( pointer >= pc_rx_buffer + sizeof pc_rx_buffer )
          {
             pointer = pc_rx_buffer;
          }
    7. It is easier to write an incorrect program than understand a correct one.
    40. There are two ways to write error-free programs; only the third one works.*

  3. #3
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    Apr 2006
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    Thanks Dave,

    Thats pretty much what I was heading towards.

    I just thought that it was a bit messy. Logically that is the equivalent of what I need to do.

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