Re: Print plot error

[Dmitri A. Sergatskov]

On Tue, Aug 25, 2009 at 10:49 AM, Ben Abbott<address@hidden> wrote:
> On Monday, August 24, 2009, at 09:32PM, "Ben Abbott" <address@hidden> wrote:
>>
>>On Aug 24, 2009, at 9:26 PM, Rob Mahurin wrote:
>>
>>> On Aug 24, 2009, at 9:14 PM, Ben Abbott wrote:
>>>> Sorry for my lack ... but will waitpid kill non-zombie children?
>>>>
>>>> There is an active gnuplot for each figure window. Would wiatid
>>>> terminate those children as well?
>>>
>>> No, see the man page for the wait4() and waitpid() system calls.
>>>
>>> waitpid(-1,0) will hang if there are children still running, but
>>> waitpid(-1,WNOHANG) will just return zero.
>>>
>>> If there are not children running, waitpid(-1,anything) should just
>>> return -1.
>>>
>>> Don't believe me, test it.
>>>
>>> Rob
>>
>>Sorry, I don't mean to question you, only trying to learn about
>>something I have no prior experience with.
>>
>>If neither of you get to it, I'll try to put together a quck changeset
>>tomorrow (attributed to you and Dmitri).
>>
>>Ben
>
> New problem. I'm presently unable to build the developers sources, and am 
> running 3.2.2 instead.
>
> octave:9> waitpid (-1,"WNOHANG")

There should be no quotes. WNOHANG is a function:

octave:1> WNOHANG
ans =  1
octave:2> help WNOHANG
`WNOHANG' is a built-in function

 -- Built-in Function:  WNOHANG ()
     Return the numerical value of the option argument that may be
     passed to `waitpid' to indicate that it should return its status
     immediately instead of waiting for a process to exit.

     See also: waitpid, WUNTRACED, WCONTINUE

Dmitri.
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