I am running a program and want to see what its return code is (since it returns different codes based on different errors).
I know in Bash I can do this by running
echo $?
What do I do when using cmd.exe on Windows?
I am running a program and want to see what its return code is (since it returns different codes based on different errors).
I know in Bash I can do this by running
echo $?
What do I do when using cmd.exe on Windows?
A pseudo environment variable named errorlevel stores the exit code:
echo Exit Code is %errorlevel%
Also, the if command has a special syntax:
if errorlevel
See if /? for details.
@echo off
my_nifty_exe.exe
if errorlevel 1 (
echo Failure Reason Given is %errorlevel%
exit /b %errorlevel%
)
Warning: If you set an environment variable name errorlevel, %errorlevel% will return that value and not the exit code. Use (set errorlevel=) to clear the environment variable, allowing access to the true value of errorlevel via the %errorlevel% environment variable.
Use the built-in ERRORLEVEL Variable:
echo %ERRORLEVEL%
But beware if an application has defined an environment variable named ERRORLEVEL!
It's worth noting that .BAT and .CMD files operate differently.
Reading https://ss64.com/nt/errorlevel.html it notes the following:
There is a key difference between the way .CMD and .BAT batch files set errorlevels:
An old .BAT batch script running the 'new' internal commands: APPEND, ASSOC, PATH, PROMPT, FTYPE and SET will only set ERRORLEVEL if an error occurs. So if you have two commands in the batch script and the first fails, the ERRORLEVEL will remain set even after the second command succeeds.
This can make debugging a problem BAT script more difficult, a CMD batch script is more consistent and will set ERRORLEVEL after every command that you run [source].
This was causing me no end of grief as I was executing successive commands, but the ERRORLEVEL would remain unchanged even in the event of a failure.