You could use the pattern "x4 (NN X8 N x4 /a N)*". Instead of skipping the length to get it later, you would fetch it twice and use it once. And at least in that case, the pattern doesn't fail on a x (actually, since the x4 in the parentheses skips the bytes read by the second N, you know that there is something to skip.

Though actually, the fact that this fails is a good thing, because you know here that for some reason, after the last chunk, there are still some bytes (between 1 and 3) that lets x4 skip at least once, but not four times in a row. IE, your data is invalid. Try unpack "H*", pack "H*", <DATA>;. It looks like pack isn't very smart with the \n at the end of the string.

In reply to Re^3: Seeking with 'x' in unpack and out of bounds reads by Eily
in thread Seeking with 'x' in unpack and out of bounds reads by mxb

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