Linda Walsh <[EMAIL PROTECTED]> writes: > I can specify the "seek=BLOCKS" param, but it appears that "dd" doesn't > translate this to a "seek" command but instead uses "read" to to > sequentially access the block device. Is this the case or am I > hallucinating?
Normally it uses lseek: $ dd --version | sed 1q dd (coreutils) 5.93 $ strace dd bs=1 seek=10 skip=20 if=/etc/motd of=/tmp/foox count=1 ... _llseek(0, 20, [20], SEEK_CUR) = 0 ... _llseek(1, 10, [10], SEEK_CUR) = 0 read(0, "-", 1) = 1 write(1, "-", 1) = 1 ... If you have devices that can't seek, it falls back on read/write. strace might tell you why. > Second question I had -- at times, it seems like various utils > are limited to 2G file offsets on OS's (i686-linux, i686-cygwin) > that support files >2G. Is this "old" behavior Yes; modern coreutils versions shouldn't have 2 GiB limits for file sizes. _______________________________________________ Bug-coreutils mailing list [email protected] http://lists.gnu.org/mailman/listinfo/bug-coreutils
