How to Download XML file from FTP in iPhone
-(void) downLoad
{

CFStringRef UpGrdURL=CFSTR("ftp://webaddress/abc.xml");
CFURLRef requestURL=CFURLCreateWithString(kCFAllocatorDefault,UpGrdURL,NULL);
CFURLRef requestLocalFile=CFURLCreateWithFileSystemPath(NULL, CFSTR("abc.xml"),
                                                        kCFURLPOSIXPathStyle, false);
CFReadStreamRef readStream=CFReadStreamCreateWithFTPURL(kCFAllocatorDefault,requestURL);
CFWriteStreamRef writeStream=CFWriteStreamCreateWithFile(kCFAllocatorDefault,requestLocalFile);
CFWriteStreamOpen (writeStream);
if (CFWriteStreamGetStatus(writeStream)==kCFStreamStatusOpen) {
    UIAlertView * alertView = [[UIAlertView alloc] initWithTitle: @"Information box."
                                                         message: [NSString stringWithFormat:@"(CFWriteStreamOpen : kCFStreamStatusOpen."]
                                                        delegate: nil cancelButtonTitle: @"OK" otherButtonTitles: nil];
    [alertView show];
    [alertView release];
}

MyStreamInfo XX;
XX.readStream=readStream;
XX.writeStream=writeStream;
CFStreamClientContext CTX = { 0, &XX, NULL, NULL, NULL };

CFStringRef UserName=CFSTR("******");
CFStringRef PassWord=CFSTR("******");
CFReadStreamSetProperty (readStream,kCFStreamPropertyFTPUserName,UserName);
CFReadStreamSetProperty (readStream,kCFStreamPropertyFTPPassword,PassWord);
CFReadStreamSetProperty (readStream,kCFStreamPropertyFTPUsePassiveMode,NO);
//  CFReadStreamOpen (readStream);
//CFReadStreamSetClient(readStream,kCFStreamEventHasBytesAvailable|kCFStreamEventErrorOccurred,  readCallBack,&CTX);

CFReadStreamSetClient(readStream, kCFStreamEventHasBytesAvailable, [self readCallBack:readStream eventType:kCFStreamEventHasBytesAvailable clientCallBackInfo:&CTX], &CTX);

}

-(void) readCallBack:(CFReadStreamRef)stream eventType:(CFStreamEventType)eventType clientCallBackInfo:(void *)clientCallBackInfo
{
char*   buffer[1024];
CFIndex bytes_recvd; //bytes read

int recv_len = 0;
int total_size;
//CFIndex bytesWritten;
//int totalBytesWritten;
//CFWriteStreamRef writeStream;
UInt8 buf[4096];

bytes_recvd = CFReadStreamRead(stream, buf + recv_len, 4096);


while(recv_len < total_size && recv_len < sizeof(buffer)) {

    bytes_recvd = CFReadStreamRead(stream, buf + recv_len, 4096);
    NSLog(@"total bytes are %d", bytes_recvd);

}
recv_len = bytes_recvd + recv_len;
}