James Bottomley <j...@linux.ibm.com> writes:
> On Wed, 2022-12-14 at 11:31 +0000, Daniel P. Berrangé wrote:
[...]
>> These days, we have a policy of not tyring to map nested data onto
>> the flat QemuOpts. This has been done in several areas and we've
>> ended up with a mess of ever so slightly different impls each with
>> their own flaws. This is why our preferred approach these days is to
>> add support for JSON syntax to enable non-flat config.
>
> Well, OK, but I've got to say on behalf of shell script writers
> everywhere that using json for command line arguments is a textbook
> definition of cruel and unusual punishment.
For new code, use qobject_input_visitor_new_str(). Parses both JSON and
dotted keys. Example: case QEMU_OPTION_blockdev in qemu_init(). Dotted
keys can fall apart for corner cases. See util/keyval.c if you're
curious.
Sometimes we bend over backwards for backward compatibility, and do
something like
if (optarg[0] == '{') {
QObject *obj = qobject_from_json(optarg, &error_fatal);
v = qobject_input_visitor_new(obj);
qobject_unref(obj);
} else {
... old parser ...
}
This parses both JSON and whatever old crap. Example:
object_option_parse().
Questions?
