Correct technique to find application in 32 and 64 bit versions of Vista/Windows 7 from CMD.EXE

Question

BACKGROUND

I have an existing CMD script that works fine. It launches an app from PROGRAM FILES like so

"%PROGRAMFILES%\MyApp\app.exe" 

PROBLEM

• it works fine on 32-bit versions of Windows (Vista, Windows 7)
• but on 64-bit versions of Windows the app will be installed into "Program Files (x86)" and not "Program Files" (which is what happens on the 32bit OS)

WHAT I AM LOOKING FOR

• A script that robustly handles both cases (i.e. it "does the right thing" depending on the OS it is on)
• a method that uses only those features found in CMD.EXE. I Am curious about solutions that use Powershell, etc, but those don't help me - Powershell will not be on the machines this script will run.

Solution 1

Similar to Matt's correct answer. Basically in this version the complete path is verified.

SET AppExePath="%ProgramFiles(x86)%\MyApp\app.exe"
IF NOT EXIST %AppExePath% SET AppExePath="%ProgramFiles%\MyApp\app.exe"
%AppExePath%

Solution 2

This is the best that I could come up with:

set strProgramFiles=%ProgramFiles%
if exist "%ProgramFiles(x86)%" set strProgramFiles=%ProgramFiles(x86)%
"%strProgramFiles%\MyApp\app.exe"

Solution 3

Basically, you need to test for for the ProgramFiles(x86) environment variable to determine if you're in 64bit Windows or not. Here's a sample batch file.

if "%programfiles(x86)%zzz"=="zzz" goto 32BIT
echo 64-bit Windows installed
"%PROGRAMFILES(x86)%\MyApp\app.exe"
goto END

:32BIT
echo 32-bit Windows installed
"%PROGRAMFILES%\MyApp\app.exe"

:END

Comments

[bjoster]

This is incomplete and may fail on some (rare - but the question was for a "robust" solution) machines. Possible values for %processor_architecture% are AMD64, IA64, ARM64, EM64T and X86 in which you script would fail in 3/5 cases.