Get the exit code from a command without capturing?

[halloleo]

I have a long running progress-lines-outputting command. In subproc mode I run it like this:

my_command arg1 arg2

Now I have a xonsh script doing exactly that and in the script, after the command ran I would like to know, what the exit code of my_command was. How can I find out? !() is no good because it captures the output as well; instead I would like the output from the command coming into the terminal character by character while my_command is running. I only need the exit code.

So what can I do to get only the exit code in my xonsh script?

Thanks for pointers!

[halloleo]

The best I could come up with is:

$RAISE_SUBPROC_ERROR = True
import subprocess

try:
    my_command arg1 arg2
except subprocess.CalledProcessError as e:
    # do things in case of failure

# normal continuation

This doesn't give the the exit code number but at least a mechanism to see whether exit code was ==0 or not.

[gforsyth]

You can use ![] for this. That creates a subproc pipeline that doesn't capture output, but has all of the other attributes of !().

ls
# a  b
a = ![ls .]  # note that output is not captured and streams to stdout
# a  b
a.returncode
# 0
a.output  # no output captured
# ''

[anki-code]

Thanks!

@halloleo feel free to create PR with updating docs.

Good example:

if r := ![ls NONONO]:
    print(f'It works! Return code: {r.returncode}')
else:
    print(f'It fails! Return code: {r.returncode}')

# ls: cannot access 'NONONO': No such file or directory
# It fails! Return code: 2

[halloleo]

Thanks for this. I will try it out.