The reason this occurs is because bash actually expands the asterisk to every matching file, producing a very long command line.
mv
Below commands enables you to copy files to $target_dir with no restriction
echo {$tmpFolder}/* | xargs mv -t {$target_dir}
Add prefix as "nice -n10" as below if you do it in the server and want to keep working other process
echo {$tmpFolder}/* | nice -n10 xargs mv -t {$target_dir}
rm
Delete all the files including directories
find . -name "*" -print0 | xargs -0 rm -r