Stupid cmd.exe tricks: Entering a directory that doesn’t exist, then immediately leaving

Raymond Chen

I discovered that cmd.exe lets you enter a nonexistent directory, as long as you leave it before anybody notices.

rem acts like cd C:\Windows
cd C:\doesnt-exist\..\Windows

rem acts like cd C:\Windows
cd C:\really\doesnt-exist\..\..\Windows

rem acts like type C:\Windows\win.ini
type C:\doesnt-exist\..\Windows\win.ini

This is handy if you have a full path to a file on the clipboard and you want to access the parent directory. For example, to chdir into the parent directory, you can type cd, a space, and then paste the full path, and then append \.. and hit Enter.

rem suppose clipboard contains C:\directory\with\file.txt
rem The next line acts like cd C:\directory\with
cd C:\directory\with\file.txt\..

This trick works because cmd.exe does some path simplification before calling into the file system. It sees the .. and says, “Oh, I can do that myself!” and uses it to counteract the previous directory. The previous directory is never accessed, so the command processor doesn’t notice that it never existed.