Xonsh option mimicing bash -x flag

Question

Is there something similar to the -x option for bash in xonsh to print every (shell) command as it runs?

Answer 1

You can set $XONSH_TRACE_SUBPROC = True to log every subprocess argument list, though it doesn't appear to expand aliases:

>>> $XONSH_TRACE_SUBPROC = True
>>> aliases["ls"] = "eza"
>>> ls -l
TRACE SUBPROC: (['ls', '-l'],), captured=hiddenobject

If you want more complex logging, you can set $XONSH_TRACE_SUBPROC_FUNC to a custom callback, like this:

>>> def tracer(cmds: tuple[list], captured: Union[bool, str] = False):
    # If you want to run any subcommands in this function, you'll have to disable tracing first in order to avoid recursion.
    $XONSH_TRACE_SUBPROC = False
    # Run `which` on the first argument of each command:
    expanded = [$(which @(cmd[0])).strip() for cmd in cmds]
    $XONSH_TRACE_SUBPROC = True
    print(f"TRACE SUBPROC: {cmds}, expand to {expanded}", file=sys.stderr)

>>> $XONSH_TRACE_SUBPROC_FUNC = tracer
>>> ls -l
TRACE SUBPROC: (['ls', '-l'],), expand to ['eza]