On some Android devices, in the ADB shell, I can only run echo, cd, ls. When I run:
echo
cd
ls
tar -cvf //mnt/sdcard/BackUp1669/a
In reply to Igor Ganapolsky, you would have to have a database set up for locate.
Probably 'find' would be adequate for your needs.
exmample:
find -name *.apk