Convert all file extensions to lower-case

Question

I\'m trying to lower-case all my extensions regardless of what it is. So far, from what I\'ve seen, you have to specify what file extensions you want to convert to lower-cas

Answer 1

This is shorter but more general, combined from other's answer:

rename 's/\.([^.]+)$/.\L$1/' *

Simulation

For simulation, use -n, i.e. rename -n 's/\.([^.]+)$/.\L$1/' *. This way you can see what will be changed before the real changes being performed. Example output:

Happy.Family.GATHERING.JPG renamed as Happy.Family.GATHERING.jpg
Hero_from_The_Land_Across_the_River.JPG renamed as Hero_from_The_Land_Across_the_River.jpg
rAnD0m.jPg1 renamed as rAnD0m.jpg1

Short explanation about the syntax

• The syntax is rename OPTIONS 's/WHAT_TO_FIND_IN_THE_NAME/THE_REPLACEMENT/' FILENAMES
• \.([^.]+)$ means sequence of anything but dot ([^.]) at the end of the string ($), after dot (\.)
• .\L$1 means dot (\.) followed by lowercase (\L) of 1^st group ($1)
• First group in this case is the extension ([^.]+)
• You better use single quote ' instead of double quote " to wrap the regex to avoid shell expansion