rename files : UPPER CASE to lower case

ls | while read file; do mv $file `echo $file | sed 's/.*/\L&/'`; done;

but does not work for file names with white space(s) in them.


replace all white spaces with underscore in any [filename.ext]:

for i in `find . -name '* *' | tr ' ' '~'`; do mv "$(echo $i| tr '~' ' ')" "$(echo $i | tr '~' '_')"; done