1

I see sometimes star symbol (*) in the hex editor, like

...
00001d0 0000 0000 0000 0000 0000 0000 0000 0000
*
00001f0 0000 0000 0000 0000 0008 0000 0000 0000
...

It is probably some sort of separator. However, there are many other separators too. What is the meaning of this star symbol in hex data?

5

It means that one or more lines were suppressed, because they are identical to the previous line; in this case, it means that the line starting at 00001e0 is all zeroes, same as that starting at 00001d0.

To determine the number of deleted lines, you need to look at the addresses involved and the length of each line; in this case, a single line was deleted.

If you're using od, this is controlled by the -v flag. By default od will suppress duplicate lines, -v tells it not to.

  • I think -v flag is not suppressing duplicate lines, so I do not see anymore duplicate lines and no star symbols. I am viewing binary data and splitting it to chunks and then converting back to smaller binary files. Do you think I should use -v flag in this kind of task? I think yes because I should not alter (suppress) the original data but just split by a deliminator. – Léo Léopold Hertz 준영 Jun 25 '15 at 10:30
  • 1
    If you're manipulating binary data by converting to and from hex dumps you could take a look at xxd instead. But yes, I'd recommend od -v if you're rebuilding the original data... – Stephen Kitt Jun 25 '15 at 21:16
  • Command od -v gives me six letter strings like 000000 042577 which I think is an octave format. Another command hexdump -v gives me also four letter stringse like 457f 464c but with some octave options hexdump -vo gives three letter words like 000000 177 105 .... I need to open a new thread for this issue here unix.stackexchange.com/q/212334/16920 – Léo Léopold Hertz 준영 Jun 26 '15 at 5:54

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