Cocoa NSOutputStream send to a connection

问题:

I am new to Cocoa, but managed to get a connection (to a FTP) up and running, and I've set up an eventhandler for the NSInputStream iStream to alert every response (which also works).

What I manage to get is simply the hello message and a connection timeout 60 sec, closing control connection.

EDIT: I guess my question is "without closing->opening what would be an non-terminating way of flushing the outputStream?

After searching stackoverflow and finding a lot of NSOutputStream write problems (e.g. How to use NSOutputStream's write message?) and a lot of confusion in my google hits, I figured I'd try to ask my own question:

I've tried reading the developer.apple.com doc on OutputStream, but it seems almost impossible for me to send some data (in this case just a string) to the "connection" via the NSOutputStream oStream.

- (IBAction) send_something: sender
{
const char *send_command_char = [@"USER foo" UTF8String];
send_command_buffer = [NSMutableData dataWithBytes:send_command_char length:strlen(send_command_char) + 1];
uint8_t *readBytes = (uint8_t *)[send_command_buffer mutableBytes];
NSInteger byteIndex = 0;
readBytes += byteIndex;
int data_len = [send_command_buffer length];
unsigned int len = ((data_len - byteIndex >= 1024) ?
                    1024 : (data_len-byteIndex));
uint8_t buf[len];
(void)memcpy(buf, readBytes, len);
len = [oStream write:(const uint8_t *)buf maxLength:len];
byteIndex += len;
}

the above seems not to result in any useable events. typing it under NSStreamEventHasSpaceAvailable sometimes give a response if I spam the ftp by keep creating new connection instances and keep sending some command whenever oStream has free space. In other words, nothing "right" and so I'm still unclear how to properly send a command to the connection. Should I open -> write -> close every time i want to write to oStream (and thus to the ftp) and can I then expect a reply (hasBytesAvailable event on iStream)? EDIT: Doesn't look like it no.

For some reason I find it very difficult to find any clear tutorials on this matter. Seems like there are more than a few in the same position as me: unclear how to use oStream write?

Please! Any little bit that can help clear this up is greatly appreciated!

If needed I can write the rest of the code.

• Chuck

回答1:

Okay, so 10 hours 28 views and no answers/comments, but that's OK, because I just solved it with some good help from a very very friendly irssi coder (no butt licking intended ;)).

He proposed that I tried to std::endl'e it (newline + flush), and so I tried simply adding the newline char (\n, 0x0A) and it worked perfectly!