Originally File.size() returns an unsigned long value, but the file size is larger than 32768, it will return an incorrect value. ``` C #include <FileIO.h> #include <Bridge.h> void setup() { Bridge.begin(); Serial.begin(9600); FileSystem.begin(); while(!Serial); File dataFile = FileSystem.open("/bin/busybox", FILE_READ); unsigned long len= dataFile.size(); Serial.println(len);//return 26544 } ``` PuTTY root@Arduino:/bin# ls busybox -l -rwxr-xr-x 1 root root 419760 Apr 10 09:11 busybox