Exit code mismatch

[eproxus]

Running erlexec with monitor as an option, I receive {'DOWN', #Ref<0.0.0.3303>, process, <0.207.0>, {exit_status, 256}}, however running the command in the shell returns the error code 1.

The command is started with:

exec:run(["/path/to/command", "--id", "1", "--control", ":3333"], [monitor, {stdout, print}, {stderr, print}, {kill_timeout, 1}])

The output and message received is:

Got stderr from 66903: <<"time=\"2015-07-16T16:18:53+02:00\" level=fatal msg=\"Could not create controller: dial tcp 127.0.0.1:23000: connection refused\" \n">>
{'DOWN', #Ref<0.0.0.3303>, process, <0.207.0>, {exit_status, 256}}

However, running the command in the shell shows the error code is actually 1:

$ /path/to/command --id 1 --control :3333
FATA[0000] Could not create controller: dial tcp :3333: connection refused
$ echo $?
1

[saleyn]

You need to use the exec:status/1 call to interpret the exit code reported by exec, which could be either a signal or status, depending on the termination cause:

2> exec:status(256).
{status,1}
3> exec:status(1).
{signal,sighup,false}

[eproxus]

Excuse my lack of knowledge, on the subject, but why? :smile: What's the difference between status and status in these contexts?

[saleyn]

The exit code returned by Linux and other OS's that support signals contains information on how the process was terminated (normally or by signal), so the value returned in {exit_status, N} needs to be interpreted by the exec:status/1 call to get the "real" exit status.

[eproxus]

I see, thanks!