Exiting batch with `EXIT /B X` where X>=1 acts as

问题:

I'm trying to chain a series of .bat files using the EXIT /B X command to return success or failure and && and || for conditional running of the next .bat (e.g. a.bat && b.bat).

Regardless of whether I call EXIT /B 0 or anything else to end a.bat, a.bat && b.bat will call b.bat afterward. My understanding is that EXIT /B 0 should set ERRORLEVEL=0, which is success, so the && should continue. The counterpoint to this is that calling EXIT /B 1 should set ERRORLEVEL=1 which is failure, so the && should stop. What am I missing here?

Trivialized example:

For non-batch commands, acting as expected:

C:\> echo test|findstr test>NUL && echo yes
yes

C:\> echo test|findstr test>NUL || echo yes

C:\> echo test|findstr nope>NUL && echo yes

C:\> echo test|findstr nope>NUL || echo yes
yes

Using EXIT /B always sees a.bat as successful:

C:\> echo @EXIT /B 0 > a.bat

C:\> a.bat && echo yes
yes

C:\> a.bat || echo yes

C:\> echo @EXIT /B 1 > a.bat

C:\> a.bat && echo yes
yes

C:\> a.bat || echo yes

How can I exit from a.bat so that a.bat && b.bat and a.bat || b.bat behave as expected?

All commands are run in cmd.exe on Windows XP SP3.

回答1:

If you ask me, exit codes in batch files are broken for this exact reason, but there is a hacky workaround you can use. As the last line of your batch file, use:

@%COMSPEC% /C exit 1 >nul

Since this is an actual process that is started you get a real process exit code and && and || will work.

回答2:

It works as it should when using call to execute batch scripts containing an exit statement:

C:\>echo @EXIT /B 1 > a.bat

C:\>call a.bat && echo yes

C:\>call a.bat || echo yes
yes

By the way, it says wrongly on Microsoft docs:

Call has no effect at the command prompt when it is used outside of a script or batch file.

回答3:

If you use start /wait you can also use this in a very simple Windows application (written in C#) called by DOS batch files like so:

static class Program
{
    [STAThread]
    static void Main(string[] args)
    {
        Environment.ExitCode = Convert.ToInt32(args[0]);
    }
}

Then the application can be called by your DOS batch file and evaluate the result. i.e.

c:> start /wait SetRC 1
c:> if "%errorlevel%"=="1" goto abort

NOTE: the /wait is not necessary in a batch file.

You could pass in the return code you want as an argument to your program.cs and get it out this way guaranteed.

回答4:

I think you are getting Errorlevel=0 with because you are indeed executing a.bat (regardless of the return code).

You would fail the check if a.bat did not exist. CALL is the only way I know to pull in the environment from a.bat.