Free space slowly decreasing on apple Mac

You don’t need to install software. I could just now examine the hidden sansa files from a mac, but don’t have time to finish giving all the right steps. If you go into mac applications/utilities/terminal.app you bring up a very powerful mode - you are a superman for good or evil and may kill your sansa or mac or the universe if not done right. So don’t try the preliminary stuff below unless either you know what you are doing or I clean up the directions a bit later. If you don’t like this approach, tough luck… it can be for other readers to see or help with.  

What I did is plug in sansa and click on mac’s terminal. In that window I did something like

cd /

ls

cd Volumes

ls

cd “SANSA CLIP”

ls -a -S

That gave me a file list: 

MTABLE.SYS .Spotlight-V100 .fseventsd MUSIC SYS_CONF.SYS

RES_INFO.SYS .Trashes AUDIBLE PODCASTS …

. ._.Trashes AUDIOBOOKS RECORD version.sdk

I have heard of that stupid useless spotlight directory that mac generates, so I experimented with “rm -r .Spotlight-V100” which removes it. you have to kill the terminal window in order to eject the sansa. I found the mac recreated it when bringing things online again, maybe the problem is the .trashes anyway. Now I just remembered I want to always use the ls -a -o option to see the sizes, which are modest in my case although it probably doesn’t include under the directory. TBD

DO NOT TRY THE BELOW STEPS, IT IS JUST TO COPY IN SOME NOTES ON SOLVING A SIMILAR PROBLEM ON THE MAC ITSELF and gives raw material to come up with relevant commands later:

For the record, if your disk space disappears, go into applications utility “terminal” and risk total meltdown with:
sudo du -h -d 1 /
…which will show the huge file. Get rid of it by
cd / (move to the top) 
ls -a (see what is there including hidden files)
sudo mdutil -i off / (turn spotlight off)
sudo rm -r .Spotlight-V100 (delete the old index)
sudo rm .metadata_never_index (delete the never index file, if there)
sudo mdutil -i on / (turn spotlight back on)