How can one batch file get the exit code of another?

I had a batch script in Teamcity pipeline and it did not exit after it's child script did exit with code 1.

To fix the problem I added this string IF %ERRORLEVEL% NEQ 0 EXIT 1 after the child script call.

main-script.bat

...some code
call child-script.bat
IF %ERRORLEVEL% NEQ 0 EXIT 1
...some code

After the child script call, exit result is save to %ERRORLEVEL%. If it did exit with error the value would be not equal to 0. So we check this and if it is the case we exit with code 1 (error).

The accepted answer is correct, but if you are using call to call another batch script, and that second batch script is using SetLocal, you may need to use a parsing trick to accomplish this. If you are running into this, add the following code before your exit b:

ENDLOCAL&set myvariable=%myvariable%

Now the value of myvariable is made available to the calling context and you can see the value in the other script.

References:
https://stackoverflow.com/a/16167938/89590
http://www.borngeek.com/2008/05/22/exiting-batch-file-contexts/

Just swap CMD /C for call.

task.bat:

@echo off
set errorlevel=15

runtask.bat

call task.bat
set taskexitcode=%errorlevel%
echo %taskexitcode%

Output

15