pv can't show progress properly

[sonnyhcl]

flash/flash

Line 632 in 0b28b5c

pv -s "${size}" < "${image}" | sudo dd bs=$bs_size "of=${rawdisk}"

In my use case, the progress soon gets 100% but the dd command is still working at 10MB/s. It seems the image is preloaded in memory.

clhu@t5 ~/w/f/sample> flash --userdata static.yml -d /dev/sdd ~/Downloads/installer/hypriotos-rpi-v1.10.0.img 

Is /dev/sdd correct? y
Unmounting /dev/sdd ...
Flashing /home/clhu/Downloads/installer/hypriotos-rpi-v1.10.0.img to /dev/sdd ...
1000MiB 0:00:02 [ 400MiB/s] [=========================================================>] 100%

[sonnyhcl]

Actually, dd is now providing a progress flag to tell you the progress.

status=LEVEL
              The LEVEL of information to print to stderr; 'none' suppresses
              everything but error messages, 'noxfer' suppresses the final
              transfer statistics, 'progress' shows periodic transfer
              statistics

flash/flash

Lines 628 to 637 in 0b28b5c

	echo "Flashing ${image} to ${rawdisk} ..."
	if [[ -x $(command -v pv) ]]; then
	sudo_prompt
	size=$(/usr/bin/stat "$size_opt" "${image}")
	pv -s "${size}" < "${image}" | sudo dd bs=$bs_size "of=${rawdisk}"
	else
	echo "No 'pv' command found, so no progress available."
	echo "Press CTRL+T if you want to see the current info of dd command."
	sudo dd bs=$bs_size "if=${image}" "of=${rawdisk}"
	fi

It's time to change this using progress flag

echo "Flashing ${image} to ${rawdisk} ..." 
sudo dd bs=$bs_size status=progress "if=${image}" "of=${rawdisk}" 

[shafer]

I don't think it is pv that is the problem. I think the problem is that dd needs flags to bypass cache(s) so that writes don't appear to finish super fast and you see the real progress. I added oflag=direct iflag=fullblock to my dd options and then the progress looks correct. I don't know if macOS supports those options. If there is interest I'm game to make a PR that adds support to the script so that the progress shown by pv reflects reality.