Add iotd program framework source code

guowenxue

2021-04-20 c7b6f4f68a6c9e8e83849601bd0f5240c47c317f

 apue/2.Socket/ds18b20.c

@@ -98,5 +98,7 @@
    /* convert string value to float value */
    *temp = atof(ptr)/1000;
   
    close(fd);

    return 0;
}