How to specify /D in FOR command?

Question

The Windows command line interpreter features a FOR command, which is able to parse the output of a given command and execute the loop for each line of the output, e.g.:

FOR /F %%i IN ('DIR .') DO echo %i # Outputs each file name

The command (DIR .) is executed in a child command line via cmd /C <command> <command-arguments>, however, the /D parameter is not specified ... this leads to weird behavior if the user has a AutoRun command with output (e.g. echo, or cls).

Is there a way to force FOR to execute the command via cmd /C /D <command> <command-arguments>?

Answer 1

You have run across one of the many design flaws of cmd.exe, and this one has bothered me for quite some time. I'm pretty sure there is no way to suppress AutoRun when FOR /F executes a command.

What makes this especially irritating is that pipes also use CMD /C (one for each side of the pipe), but the designers of the pipe were smart enough to incorporate both the /D and /S options. It is really a shame the designers of FOR /F couldn't have done the same.

I believe your only recourse One option is to be defensive within your AutoRun command definition. I suggest putting all the AutoRun commands within a batch script that has something like the following at the top:

@echo off
if defined AutoRunComplete exit /b
set AutoRunComplete=1
REM Put your AutoRun commands below...

But if you cannot control the AutoRun commands, then I think you are out of luck. Aacini's idea of using a temporary file to get around the problem is an effective and simple solution.

Answer 2

A very simple solution for your problem is use a file in the for /F command instead of a command. This way, we just emulate the internal operation of for /F over a command, but executing each step explicitly: 1. Execute the command and store its output in a temporary text file. 2. Process all lines in the temporary file. 3. Delete the file.

DIR . > TempFile.txt
FOR /F %%i IN (TempFile.txt) DO echo %%i
DEL TempFile.txt