thx to

note (thx if you do something like 'ls *', files whose name starts with '-' will be interpreted as arguments to 'ls'! Instead, if you are concerned about security, you should do either/both of 'ls ./*' or 'ls -- *' (-- means 'end of option list')

if you hit cntl-S in a terminal it freezes everything! hit cntl-Q to unfreeze.