FtpRead - Read data from a remote file or directory.
int FtpRead(void *buf, int max, netbuf *nData);
buf Specifies the address of a buffer where received data will be
max Specifies the size of the user’s buffer.
nData A handle returned by FtpAccess().
FtpRead copies up to max bytes of data from the specified data
connection and returns it to the user’s buffer. If the data connection
was opened in ascii mode, no more than one line of data will be
Returns the number of bytes written to the user’s buffer or -1 on error
or end of file.