Online Lower Case Converter

I have to rename a complete folder tree recursively so that no uppercase letter appears anywhere (it's C++ sourcecode, but that shouldn't matter). Bonus points for ignoring CVS and SVN control files/folders. Preferred way would be a shell script, since shell should be available at any Linux box.

There were some valid arguments about details of the file renaming.

1. I think files with same lowercase names should be overwritten, it's the user's problem. When checked out on a case-ignoring file system would overwrite the first one with the latter, too.

2. I would consider A-Z characters and transform them to a-z, everything else is just calling for problems (at least with source code).

3. The script would be needed to run a build on a Linux system, so I think changes to CVS or SVN control files should be omitted. After all, it's just a scratch checkout. Maybe an "export" is more appropriate.

I have a database table with a code column that uses a lowercase index to prevent code values that only differ in case (e.g. 'XYZ' = 'xYZ' = 'xyz'). The typical way in Postgresql is to create a function based index, like this: CREATE UNIQUE INDEX mytable_lower_code_idx ON mytable (lower(code)).

Now I have a case where I need upsert behaviour on that column:

-- first insertINSERT INTO mytable (code) VALUES ('abcd');-- second insert, with upsert behaviourINSERT INTO mytable (code) VALUES ('Abcd')  ON CONFLICT (code) DO UPDATE  SET code='Abcd';

For the second insert I get a unique key violation: ERROR: duplicate key value violates unique constraint "mytable_lower_code_idx"

(I also tried to use ON CONFLICT ON CONSTRAINT mytable_lower_code_idx but Postgresql tells me that this constraint does not exist so maybe it doesn't treat the index as a constraint.)

My final question: Is there any way to make INSERT ... ON CONFLICT work together with indexes on expressions? Or must I introduce a physical indexed lowercase column to accomplish the task?

Is there a way to convert a string from uppercase, or even part uppercase to lowercase?

E.g. Kilometers --> kilometers.

How can I convert all values in an array to lowercase in PHP?

Something like array_change_key_case?

I got a one dimensional array of strings in java, in which i want to change all strings to lowercase, to afterwards compare it to the original array so i can have the program check whether there are no uppercase chars in my strings/array.

i've tried using x.toLowercase but that only works on single strings.Is there a way for me to convert the whole string to lowercase?

Kind regards,Brand