chriskelly chriskelly - 9 months ago 55
Node.js Question

child_process not returning correct exit code from batch file

I'm trying to get the correct exit code from a batchfile using nodejs on Windows.

When run from the command line I see the expected error code:

ml.bat profile bootstrap

ERROR: [".../deploy/lib/RoxyHttp.rb:362:in
block in request'", ".../deploy/lib/RoxyHttp.rb:352:in
loop'", ".../deploy/lib/RoxyHttp.rb:352:in
request'", ".../deploy/lib/MLClient.rb:110:in
go'", ".../deploy/lib/server_config.rb:1963:in
get_sid'", ".../deploy/lib/server_config.rb:2056:in
bootstrap'", "deploy/lib/ml.rb:168:in `'"

I verify that there exit code was non-zero:

echo %errorlevel%


Below is the correspoinding code I use in NodeJS - which always gives an exit code of 0:

var stdout = "";
let proc = child_process.spawn("ml.bat", ["profile", "bootstrap"], {shell:true});

proc.stdout.on('data', d => stdout += d.toString() + '\n';);
proc.on('close', exitcode => {

if (exitcode !== 0) {
console.log('ERROR in command');

I have tried using several variations (exec, execSync, spawnSync) and options (shell, "cmd.exe /c") but I can never get a non-zero code using node. The program does not print any output on stderr.

Any idea how to get back the right error code in NodeJS?


To solve the problem, I added the following last line to ml.bat:

exit /b %errorlevel%

Now it behaves identically on both windows and linux.