in reply to Re^5: Unique filenames with Time::HiRes
in thread Unique filenames with Time::HiRes

when you read the files in directory order, as long as you don't sort the files, you'll get them in the order they were created.

I think you're making a huge assumption there about the filesystem. perldoc -f readdir and man 3 readdir say nothing about the order of the directory entries they give you.