readLine.m

NSMutableString *string = [[NSMutableString alloc] init];
int readBytes = 0;
do {
   uint8_t buf[MPD_LINE_MAX + 1];
   memset(buf, '\0', MPD_LINE_MAX + 1);

   readBytes = [input read:buf maxLength:MPD_LINE_MAX];
   [string appendFormat:@"%s", buf];

   NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
   [string enumerateStringsMatchedByRegex:@"(.+)\n" usingBlock:^(int count,
                                                                 NSString * const cap[],
                                                                 NSRange const ranges[],
                                                                 volatile BOOL * const stop) {
         NSString *line = cap[0];
         *stop = NO;

         if ([commands count] == 0 && ![self isParsing]) {
            [self disconnect];
            [self performSelectorOnMainThread:@selector(unexpectedMessage)
                                   withObject:nil
                                waitUntilDone:NO];
            return;
         }

         if (![self isParsing]) {
            int command = [[commands objectAtIndex:0] intValue];
            [commands removeObjectAtIndex:0];

            self.parser = [[MPDParser alloc] initWithConnection:self
                                                        command:command];
            [parser release];
         }

         [parser parseLine:line];
      }];
   [string replaceOccurrencesOfRegex:@"(.+)\n" withString:@""];
   [pool drain];
} while(readBytes == MPD_LINE_MAX);
[string release];