Question about the Append?

[Wei Zhang]

Hi,

I wrote a simple application to try out the (O_WRONLY | O_APPEND) mode, and I noticed the following:

1. After writing 10MB data to an newly created empty file, I saw the file size has grown to 64MB, which is equal to the chunk size.

2. After the write, I want to know the correct file size, so I called Tell(), but it returned 0.

3. After closing the fd, I also tried Stat(), but it returned 64MB.

4. I tried both RecordAppend() and Write(), I saw the same results.

My questions:

1. What is the underline difference between normal Write() and RecordAppend()?

2. What's the proper usage of RecordAppend()?

3. How do I know "where is my written data" under the append mode? Normally I would expect the current position of file pointer is the starting position for the next append.

Your help is greatly appreciated!

Wei