For loop in CMD... how to loop A to Z (for drive letters)

Question

How can I get drive the valid drive letters from A to Z with the "for loop" in windows command line (cmd.exe)?

Example, list all files in a drive root folder, should be something like (conceptual):

for %f in (A..Z) do dir %f:\

or aproximating existing functionality:

for /L in (A, Z, 1) do echo %f:\

Answer 1

Close, but it's more like this.

for %%p in (A B 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 not exist %%p:\nul set FREEDRIVELETTER=%%p

EDIT: Here is a powershell way, not sure if off-topic for your needs

Loops the Upper Case Alphabet

65..90 | foreach {[char]$_;Write-Host "Do Something"}

or Lower Case Alphabet

97..122 | foreach {[char]$_;Write-Host "Do Something"}

Maybe this will work from a batch file.

@ECHO OFF
start /b /wait powershell.exe "97..122 | foreach {$a=[char]$_ ;dir $a:\}"
PAUSE

Answer 2

To loop through all drive letters without explicitly stating them you could use forfiles (which is delivered with all Windows versions past Vista, I believe) and its capability to expand hex. codes 0xHH, together with exit to set the exit code and the hidden variable =ExitCode to convert the exit code to a hexadecimal value, like in this example code:

@echo off
for /L %%C in (0x41,1,0x5A) do (
    cmd /C exit %%C
    for /F %%D in ('
        forfiles /P "%~dp0." /M "%~nx0" /C "cmd /C echo 0x%%=ExitCode:~-2%%"
    ') do echo %%D:\
)

This is quite slow though, because there are several cmd instances opened and closed.

---

To loop through all available drives, including network drives and also such established by subst, you could use the following code, based on wmic:

for /F "skip=1" %%C in ('wmic LogicalDisk get DeviceID') do for /F %%D in ("%%C") do echo %%D\

To loop through all local drives, you could use the following code, again based on wmic:

for /F "skip=1" %%C in ('wmic Volume where "DriveLetter is not Null" get DriveLetter') do for /F %%D in ("%%C") do echo %%D\

To loop through all local drives, but based on mountvol, you could use the following code instead:

for /F %%C in ('mountvol ^| find ":\"') do echo %%C

Finally, for the sake of completeness, to loop through all drives that have been established by subst, use the this code:

for /F "delims=\" %%C in ('subst') do echo %%C\