Renaming multiple files

If you need to rename a larger number of files following a certain pattern, you will find the 'rename' command very useful,all you need to know is the basics of regular expressions to define how the renaming should happen.

For example, if you want to add a '.old' to every file in your current directory. This will do it:

rename 's/$/.old' *

Or if you want to turn every filename lowercase:

rename 'tr/A-Z/a-z/' *

To remove all double characters you can use:

rename 'tr/a-zA-Z//s' *

Or you have many JPEG files that look like "dsc0000154.jpg" but you want the first five zeros removed as you don't need them:

rename 's/dsc00000/img/' *.jpg

You can use any Perl operator as an argument, read the documentation here:
http://perldoc.perl.org/perlop.html#Regexp-Quote-Like-Operators