Is there a system-wide text manipulation app that enables you to select text and convert all letters to upper case or lower case, like a code text editor would?
5 Answers
You can set this up as a right click service in automator as @Matthieu Riegler suggested.
Open up Automator.app and create a “Service” with this workflow.
Pay close attention to the checkbox up top, “Output replaces selected test”. After the workflow is in place and saved, navigate to “System Preferences-->Keyboard.” On the left hand side select “Services”. On the right hand side you will see the Service you created, in the example its saved as “UpperCase”. Then give it a shortcut by pressing “Add Shortcut” and give it what you would like. Tested in TestWrangler and TextEdit.
Script used in Automator:
on run {input, parameters}
set upperCaseString to ¬
(do shell script ("echo " & input & " | tr a-z A-Z;"))
return upperCaseString
end run
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1That's enough for 'English' language, but you can also add diacritical translation, like so set upperCaseString to ¬ (do shell script ("echo " & input & " | tr a-zäáà A-ZÄÁÀ;")) add an specials to your list like ä, ß and so on– RuskesFeb 9, 2015 at 18:11
I am on Mountain Lion 10.8.5 and for all editable text I can select and right click the text and choose Transformations -> Make Upper Case
.
However, it seems this does not work in all applications. TextWrangler for example does not show this menu. All system applications (Finder, TextEdit, Mail, Calendar, etc...) do.
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1
Another tool that I use is PopClip
The application can transform selected text to UPPERCASE or even Proper Case or lowercase. There are several settings for search and other context relevant actions.
I am not affiliated with the developer.
This is a sample based editing this answer...

I had the same struggle so I create a one button app that solves this problem. It looks like this:
You'll find the Lowly app here :)
WordService will solve your problem. It's a free app from Devon Technologies that provides system-wide Services that do various text manipulations, including changing case.