int WriteComPort (int fd, char * data, int datalength)
{
fd_set fs_write;
struct timeval tv_timeout;
int retval, len, total_len;
FD_ZERO (&fs_write);
FD_SET (fd, &fs_write);
tv_timeout.tv_sec = TIMEOUT_SEC (datalength, GetBaudrate ());
tv_timeout.tv_usec = TIMEOUT_USEC;
for (total_len = 0, len = 0; total_len < datalength;) {
retval = select (fd + 1, NULL, &fs_write, NULL, &tv_timeout);
if (retval) {
len = write (fd, &data[total_len], datalength - total_len);
if (len > 0)
total_len += len;
}
else {
tcflush (fd, TCOFLUSH); /* flush all output data */
break;
}
}
return (total_len);
}
int WriteComPort (int fd, unsigned char *data, int datalength)
{
int retval, len = 0, total_len = 0;
int i;
FD_ZERO (&fs_write);
FD_SET (fd, &fs_write);
tv_timeout.tv_sec = TIMEOUT_SEC (datalength, GetBaudrate ());
tv_timeout.tv_usec = TIMEOUT_USEC;
for (total_len = 0, len = 0; total_len < datalength;)
{
retval = select (fd + 1, NULL, &fs_write, NULL, &tv_timeout);
if (retval)
{
len = write (fd, data+total_len, datalength - total_len);
if (len > 0) {
total_len += len;
}
}
else if(retval == 0)
{
printf("WriteComPort timeout \n");
break ;
}
else {
printf("select return error %d\n",retval);
//tcflush (fd, TCOFLUSH); /* flush all output data */
break;
}
}
tcdrain(fd);
//usleep(500);
#if 0
printf("write: ");
for(i=0;i<total_len; i++)
printf("0x%02x ",data[i]);
printf("(total_len = %d)\r\n",total_len);
#endif
if(total_len != datalength)
{
printf("WriteComPort error \n");
return -1;
}
else
return 0;
}
int ReadComPort (int fd, void *data, int datalength)
{
fd_set fs_read;
struct timeval tv_timeout;
int retval = 0;
FD_ZERO (&fs_read);
FD_SET (fd, &fs_read);
tv_timeout.tv_sec = TIMEOUT_SEC (datalength, GetBaudrate ());
tv_timeout.tv_usec = TIMEOUT_USEC;
retval = select (fd + 1, &fs_read, NULL, NULL, &tv_timeout);
if (retval)
return (read (fd, data, datalength));
else
return (-1);
}
