Rename files

Shell Programming and Scripting
1

I wrote a script that accepts filenames as argument but I am having difficulty if filename has both(uper/lower) cases..so I want to write a script that accepts one or more filenames as arguments and converts filenames to uppercase..(actually rename files..)

2 
echo "your_file_name " |tr [:lower:]  [:upper:]
3 
rename 'y/a-z/A-Z/' *