Re: [Qemu-devel] [PATCH] New scriptarg=... -net parameter allows passing of an argument

[Anthony Liguori <anthony@codemonkey.ws>]

Avi Kivity wrote:
> Anthony Liguori wrote:
>> Ian Jackson wrote:
>>> Previously, network scripts would have to do all of their work based
>>> only on the script name and interface name.  If the script's behaviour
>>> is supposed to be different for different network interfaces this
>>> might involve constructing a special script for each interface with
>>> the associated need to delete it etc.
>>>   
>>
>> env args should get passed down to the script although I can see an 
>> argument for being able to specify this in -net.  My only suggestion 
>> would be to use an env arg instead of "$2" as it will make it easier 
>> to extend in the future.
>
> Environment variables are global, whereas scriptarg is per-interface.  
> Consider the case where scriptarg denotes the bridge name we want the 
> interface to attach to.

Right, what I'm suggesting is that scriptarg=... use an environmental 
variable (for instance, named SCRIPTARG) when executing the actual 
script instead of passing it as the second parameter.

It's nicer IMHO because it extends well to passing more data to the 
script (like whatever the -name parameter is).

I was originally going to suggest arbitrary ,key=value be passed by 
default as environmental variables like QEMU_key=value but I think that 
would get too complicated given the current code.

Regards,

Anthony Liguori