I thought Linux was case-sensitive?
 

I have had this happen to me a couple times, though.


Excuse me? Why does this happen? Is it a bug in gnu mv's regex?

I just created a file named TelTempControl.pdf and tried your command, works fine here. May it be possible that the file resides on a partition with a filesystem that is not case-sensitive?

It was on a flash drive.

The type of drive tells us nothing about the file-system. Was it possibly formatted as FAT16/32? This filesystem is not case-sensitive, so Linux is not able to execute operations on it that need case-sensitivity.

My reaction exactly as per TobiSGD :)

File systems are (or are not...) case-sensitive.

Flash-drives are customarily initialized with FAT32, which is a case-insensitive file system. Linux, of course, understands this perfectly, and behaves appropriately.

(Incidentally: Windows is no slouch on this department, either. It, too, has "installable file system" (IFS) support, although FAT and NTFS are the only drivers that are installed by default.)

So, is there a better file system to use for flash drives?

If you want to use that device with Windows (Windows 2000 and later) machines also then NTFS is the way to go, otherwise I would use ext2/3/4 for it.