adb push: sync but not copy adb push seems to push everything into the dest folder regardless of their changed/unchanged states. So it wastes a lot of time. Is it possible to sync rather than copy (i.e. to rsync rather than cp)?

I see adb has a sync option, but I'm not quite sure whether it's relevant or not.
You would use adb push --sync, for example:

adb push --sync /home/abc/ /sdcard/abc


from adb --help:


file transfer:
 push [--sync] LOCAL... REMOTE
     copy local files/directories to device
     --sync: only push files that are newer on the host than the device



but it seems that this function is available for relative newer ADB version such as version 1.0.40.