Perhaps I should add some context.
Running:
yes | dd ibs=1 count=1
reports that 512 bytes are read:
512+0 records in
1+0 records out
Only one byte should be read, as occurs with GNU and busybox dd:
1+0 records in
0+1 records out
I believe the reason for this bug in sbase is because of the comparison
with obs in the below loop, which overlooks cases such as these.
All feedback is welcome. Is this an appropriate fix to the bug?
phoebos
On Tue, Nov 22, 2022 at 16:28:35 +0000, phoebos wrote:
> Previously, running `dd ibs=1 count=1` read 512 bytes rather than 1.
> ---
> dd.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/dd.c b/dd.c
> index 6061048..4081eca 100644
> --- a/dd.c
> +++ b/dd.c
> @@ -174,7 +174,7 @@ main(int argc, char *argv[])
> /* XXX: handle non-seekable files */
> }
> while (!eof && (count == -1 || ifull + ipart < count)) {
> - while (ipos - opos < obs) {
> + while (ipos - opos < obs && ifull + ipart < count) {
> ret = read(ifd, buf + ipos, ibs);
> if (ret == 0) {
> eof = 1;
> --
> 2.38.1
>
