There are many ways to change text on the Linux command line from lowercase to uppercase and vice versa. In fact, you have an impressive set of commands to choose from. This post examines some of the best commands for the job and how you can get them to do just what you want.
The tr (translate) command is one of the easiest to use on the command line or within a script. If you have a string that you want to be sure is in uppercase, you just pass it through a tr command like this:
$ echo Hello There | tr [:lower:] [:upper:] HELLO THERE
Below is an example of using this kind of command in a script when you want to be sure that all of the text that is added to a file is in uppercase for consistency: