>files were not always files and strange behavior would occur in fringe use cases.
coughs in Unix
coughs in Unix
You can even get it using the Unix path slashes in the 2.11 source code.
(udev assumes they live under /dev. I'm not sure if /dev is hardcoded in udev or configurable. But you don't have to use udev anyway, you can create device nodes manually.)
So there's actually a good reason for being able to create device nodes outside /dev.
You either have persistent files with special attributes that identify it as a device, or you namespace your devices with characters that cannot be used in a file name. But you don't allow your devices to be valid file names and have them invisible on the file system.
I never thought about it, but when you consider ‘:’ as the device suffix, this makes directory structures make more sense to me on Windows.
C:\foo\bar makes more sense to me if it is the ‘C:’ device. Calling it a ‘C drive’ with a separate namespace never made sense to me. Somehow thinking of it the ‘C:’ device in an anonymous global hierarchy makes more sense to me.
You'll still be able to create named pipes (mkfifo), but mknod will fail.
This is handy for filesystems with a poorly developed sense of user ownership and permissions, say, msdos or vfat.
I tend to mount my /tmp space nodev and nosuid, as occasionally you'll find poorly-written, or nefariously-intended programs attempting to do such things there.