errorlevel in a for

[colargol]

Hi

this problem makes me crazy

wavi.exe is a command line tool that write to sdterr and return errorlevel 0 in case of success

so this works:

Code: Select all

wavi.exe test.avs 2>&1
echo %errorlevel%

and this:

Code: Select all

for /f "usebackq tokens=4 delims=,: " %%a in (`"wavi.exe test.avs 2>&1"`) do (
   echo channels=%%a
)

echo %errorlevel%

works perfectly but errorlevel keep the value it has before the loop
So I can't guess if my command worked or not.

Is this due to the loop. How should I do?
Thanks for help!
colargol

[aGerman]

You could try a small workaround

Code: Select all

for /f "usebackq tokens=2 delims=,:" %%a in (`"wavi.exe test.avs 2>&1"`) do (
  for /f %%b in ("%%a") do set /a n=%%b
)
echo channels=%n%

For my understanding if %n% equals 0 it failed.

Regards
aGerman

[colargol]

I had to do something like this.
Thank you aGerman

But I still don't understand why errorlevel value never changes if I put the command line into a for

[aGerman]

As far as I figured out the command line inside of a FOR /F loop is either executed in another thread of the same cmd instance (in case of internal commands) or it is executed in another instance of cmd. However it seems there is no chance to pass the errorlevel to the parent process.

Regards
aGerman

[colargol]

Interesting!
Thanks for explanations