How do i change all text in a file from uppercase to lowercase using tr?

[hawksbill]

Man page for tr: https://www.lightnetics.com/post/3335

To change the text in a file from uppercase to lowercase.

$ cat samplefile | tr '[:upper:]' '[:lower:]'

Redirect the output to another file to save the changes.

$ cat samplefile | tr '[:upper:]' '[:lower:]' > mysavefile