Re: NSTask and pseudo TTY
Re: NSTask and pseudo TTY
- Subject: Re: NSTask and pseudo TTY
- From: "James W. Walker" <email@hidden>
- Date: Sun, 28 Mar 2010 12:18:33 -0700
On Mar 28, 2010, at 12:06 PM, John Pannell wrote:
> Hi James-
>
> Depending on your use case, you might be able to shut the buffering off by something like this...
>
> setvbuf(stdout, NULL, _IONBF, 0);
That would go in the command line tool, not in the client app, right? As I mentioned, I don't have source code for the tool.
> On Mar 28, 2010, at 12:56 PM, James W. Walker wrote:
>
>> I've been running NSTask and reading the output using -[NSFileHandle readInBackgroundAndNotify], but in certain situations there was a problem: Due to the block buffering of standard output, I wasn't getting notified as soon as some output had been produced. I don't have control over the code being run by NSTask. Some googling led me to believe that I need to use a pseudo tty instead of NSPipe to communicate with the NSTask. So, I called openpty, wrapped the file descriptors in NSFileHandles, set the slave handle as standard output of the NSTask, and called [masterHandle readInBackgroundAndNotify]. This almost worked. The problem is that I can't tell when the output is done. When I was using NSPipe, my NSFileHandleReadCompletionNotification observer method would get an NSData of length 0, which told me that there was no more data. Now, that doesn't happen. I tried observing NSTaskDidTerminateNotification, but that notification arrives before I've received all the data. Attempting to read more data with -[NSFileHandle availableData] just hangs.
>>
>> Can anyone lead me out of this mire?
>>
>> _______________________________________________
>>
>> Cocoa-dev mailing list (email@hidden)
>>
>> Please do not post admin requests or moderator comments to the list.
>> Contact the moderators at cocoa-dev-admins(at)lists.apple.com
>>
>> Help/Unsubscribe/Update your Subscription:
>>
>> This email sent to email@hidden
>
_______________________________________________
Cocoa-dev mailing list (email@hidden)
Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden