Re: waiting for asynchronous processes

[Perry Smith <pedzsan@gmail.com>]

On Oct 15, 2011, at 5:24 PM, Štěpán Němec wrote:

> On Sat, 15 Oct 2011 19:20:44 +0200
> Perry Smith wrote:
> 
>> I started looking for a built in way to wait for an asynchronous command to
>> complete and discovered that I had written one long long time ago in a galaxy
>> far far away.
>> 
>>> (defun wait-for-async-process ( proc )
>>>  "Wait for PROC to finish"
>>>  (while (null (eq (process-status proc) 'exit))
>>>    (accept-process-output)))
> 
> Looks like a terrible hack to me.
> 
>> I went ahead and looked for something like it in the distribution but didn't see it.
>> 
>> I'm curious if I overlooked it.
> 
> I doubt it. If you want to wait for the process in the way you seem to
> want to wait for it, why don't you just use a synchronous process to
> begin with? If you _do_ want the non-waiting advantage of asynchronous
> processes, the usual way to handle state changes (s.a. when the process
> finishes) is to use sentinels, see e.g. (info "(elisp)Sentinels").

Well, as I said, what I really wanted to use is "grep" (the built in emacs function).  
I assumed I couldn't reach in and change him from asynchronous to synchronous -- can I?

pedz