Quirky behavior - converting to lower case

[Dick Johnson]

Using: TCC 32.10.21 x64

I use this to convert all the files in a folder to all lower case.

for /o:n %a in (*.mp4 *.mkv) do (ren "%a" "%@lower[%a]")

99% of the time it works perfectly , but every once in a while it randomly deletes the extension of a file. I just ran it on a folder containing 35 files and it deleted the extension of 3 of the files.

What am I doing wrong?

 

[Alpengreis]

I think you do nothing wrong.

Maybe that's a "speed" problem.

You could try with a little delay like the following:

for /o:n %a in (*.mkv *.mp4) do (delay /m 30 & ren "%a" "%@lower[%a]")

OR you could try it with "move" instead "ren", with something like that ...

for /o:n %a in (*.mp4 *.mkv) do (move "%a" "%@lower[%a_]") & move *.mp4_ *.mp4 & move *.mkv_ *.mkv

 

[Dick Johnson]

Thank you for your suggestion, I will try it.

But why would TCC ever delete the extension when changing a file name to lower case? Seems like there is a bug in TCC somewhere.

 

[Alpengreis]

Thats a good question. Maybe it's really a timing problem (file is locked yet or something like that). I had - not the same - but also weird behavior some years ago through timing problems with a sync process (via TCC) with an external drive) with setting of attributes (archive). But I could solve it with a little "delay" (added /G param for the command to display the percent progress - that was enough already). I had no problem over similar task with the native command line (CMD). Also possible is that an security software (AV scanner) has influence. I could never find out the REAL problem behind (also not analyzed long).

So, I am not sure if that is really a bug - for me it sounds more like problem as I described above. BUT I AM NOT SURE ABOUT!

Here, I tested with your command line with 45 files (multiple times) - was all correct.

However: annoying such things, I know!

PS: Technically, I would say: it does not a basically delete the suffix - instead it can't finish the process of renaming. The end result is the same of course.

 

[vefatica]

Is there anything peculiar about the names of the files that lose their extension? What happens if you repeat the experiment with a copy of the same set of files; are the same ones affected? You might try repeating the experiment alternating between @LOWER and @UPPER.

I tried with a few hundred files, several times, using your command verbatim, and got no misbehavior.

 

[Eric Pement]

Is there anything peculiar about the names of the files that lose their extension? What happens if you repeat the experiment with a copy of the same set of files; are the same ones affected? You might try repeating the experiment alternating between @LOWER and @UPPER.

Following up on Vince's question, include things like multiple periods in the filename or embedded spaces, as well as special symbols or characters,