Windows Command Line – Setting ERRORLEVEL to 0

batch filecommand linewindowswindows-error-reporting

I have a batch file that is a wrapper around an installer. This batch file checks the error level returned by the installer and prints accordingly.

I noticed that if I execute set ERRORLEVEL=0 in a command prompt right before kicking off the batch file (in the same command window/environment), the installer never messes with the errorlevel and my batch script always returns passed. I would assume %ERRORLEVEL% is a variable defined by Windows and is used specifically to print out errors from programs and scripts and that using the variable in a batch file or something else would be 'at your own risk' because it could be changed at any moment by another process.

From what it seems like, when I set errorlevel in the given environment, it then somehow terminates the use of errorlevel as a holder of the exit code. Does anyone know why this is? To me its just weird unexpected behavior. Any information on the subject would be greatly appreciated!

Best Answer

You are redefining the system variable into a regular one. When you do this, the system will not use it until the command session is closed.

The best way would be to use

exit /b 0

in another batch file and call it from your primary script. Where the number 0 is your wanted errorlevel. Either that or use a command that resets the errorlevel for you, such as echo, findstr etc.

For example the following commands would all set ERRORLEVEL to 0 within your batch-file:

VERIFY > nul

cmd /c "exit /b 0"

ver > nul

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Windows – Set and Get Environment Variables from Command Prompt

To make the environment variable accessible globally you need to set it in the registry. As you've realised by just using:

set NEWVAR=SOMETHING

you are just setting it in the current process space.

According to this page you can use the setx command:

setx NEWVAR SOMETHING

setx is built into Windows 7, but for older versions may only be available if you install the Windows Resource Kit

Open a command prompt and setting the default path

Assuming you want specifically a batch file to be clickable directly on Windows desktop, a simple, yet not elegant way, would be to use the following code in batch file:

@cd d:\Code
@set JAVA_HOME=C:\Jdk.1.6"
@cmd.exe /K

It will set the path and the variable, and in that context launch a nested command session with /K parameter - which will force it to wait for user input (instead of disappearing).

A more elegant solution would be to create a new shortcut on the desktop and configure it as follows:

Command: cmd /K set JAVA_HOME=C:\Jdk.1.6
Start in: d:\Code

Best Answer

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Windows – Set and Get Environment Variables from Command Prompt

Open a command prompt and setting the default path

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