Pádraig Brady <[EMAIL PROTECTED]> wrote: > Jim Meyering wrote: >> Pádraig Brady <[EMAIL PROTECTED]> wrote: >>> dd handles skip weirdly >>> >>> disk=/dev/sda8 >>> dd if=$disk bs=8M count=1 skip=1000 of=/dev/null #ok >>> dd if=$disk bs=8M count=1 skip=1000K of=/dev/null #reads whole disk! as >>> seek fails >>> >>> I had a 10s look at the source and noticed a comment >>> saying POSIX doesn't specify what we should do when >>> skipping past the end of input. For seekable files though, >>> reading the whole thing is unexpected to me at least. >>> I would expect it to do: >>> >>> if (seekable && !seek(skip_len)) >>> exit(EXIT_FAILURE); >> >> Thanks, but the existing behavior is deliberate, and IMHO, necessary. >> >> skip=N is required to try to seek, and failing that, position >> the read pointer by calling read. That is so it works on >> e.g., redirected stdin as well as on regular files. > > redirected stdin is seekable. > Note the logic I presented above.
Hi Pádraig, Redirected stdin is seekable, as long as it's from a seekable file. I meant "piped stdin". Same holds for any other non-seekable input source. I think if you try the code above, it will cause test failures. _______________________________________________ Bug-coreutils mailing list Bug-coreutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-coreutils
