exit code from mtee instead piped process even with /E

[s0nic9]

Hi, sorry for my english,
it seems mtee keep return an errorlevel code itself , instead errorlevel code of the piped process.
I've a 259 error code with mtee, I have 0 errorlevel with process output with >log.txt
Any idea ?
Thanks in advance for your job.

[ztou]

same issue here, sometimes it could return expected exit code, but most of time, it will exit with 259.

call test.bat

"test.bat log..."
3

call test.bat | mtee.exe /E 1.log

"test.bat log..."
259

[andry81]

I had hit the same issue. I beleave it is some kind of synchronization or race condition issue in the expressions like this:

a | b

1. b can start before a
2. a can exit before start b

I think the case 2 happens here because if try to add some pause or sleep command into the a like:

pathping localhost -n -q 1 -p 100 >nul 2>&1

, where 100 is milliseconds

The issue disappears. In mine case 30 milliseconds was enough.

But in some cases even 50 ms is not enough.

[andry81]

For those who suffers from the issue, there is a better implementation without need an explicit pipe from cmd.exe: https://github.com/andry81/contools/tree/HEAD/Utilities/src/callf/help.tpl

You can run instead of:

call test.bat | mtee /E 1.log

This:

callf.exe /ret-child-exit /tee-stdout 1.log /tee-stderr-dup 1 "" "cmd.exe /c call test.bat"

It is better because it can pipe stdout separately from stderr and you can even pipe between processes with Administrator privileges isolation using named pipes.