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Re: Writing NSString to a file descriptor

On 20 Nov 2007, at 18:47, AstroK Software wrote:

Just to test this possible solution I wrote the following test code:

- (void)useTool
{
NSString *msgStr = [[NSString alloc] initWithContentsOfFile: [[NSBundle mainBundle] pathForResource:@"test" ofType:@"spam"]];
NSData *msgData = [msgStr dataUsingEncoding:NSASCIIStringEncoding];
NSPipe *pipe = [NSPipe pipe];

The first problem is that this pipe is autoreleased, as another poster pointed out

NSFileHandle *fh = [pipe fileHandleForWriting];

The second problem is that here you have a file handle that is only good for *writing*...

	[[NSNotificationCenter defaultCenter] addObserver:self
						 selector:@selector(getData:)
						name:NSFileHandleReadCompletionNotification
						object:fh];
	[fh readInBackgroundAndNotify];


...and here you're trying to read from it.

The file handles you get from NSPipe are unidirectional file handles, like the ones you get from the UNIX pipe() function. It sounds to me like you're going to need a UNIX domain socket instead (sockets are bidirectional, so you can use the same file handle for reading and writing, though you'll still need one at each end).

Consider using socketpair() to create a pair of connected, unnamed, UNIX domain sockets. You can then use NSFileHandle or NS/CFStream as appropriate.

Kind regards,

Alastair.

--
http://alastairs-place.net


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 >Writing NSString to a file descriptor (From: AstroK Software <email@hidden>)



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