Freexploit original article
principle:
The if command cannot be used to test the directory, but the NUL device does exist in each directory. Therefore, it is possible to determine if the directory exists by testing the zero device. The following examples can test the existence of the directory:
IF exist c: mydir / nul goto process @echo offrem test in win2k & winxp by allyesnoclsfor %% I IN (C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z) do if exist %% i: / NUL Echo %% i drive can use & DIR %% i: | Find "available" AB two drives There is no reason to think about it.
