Reading integers from binary file in Python

The read method returns a sequence of bytes as a string. To convert from a string byte-sequence to binary data, use the built-in struct module: import struct print(struct.unpack(‘i’, Note that unpack always returns a tuple, so struct.unpack(‘i’,[0] gives the integer value that you are after. You should probably use the format string … Read more

How does a 32 bit processor support 64 bit integers?

Most processors include a carry flag and an overflow flag to support operations on multi-word integers. The carry flag is used for unsigned math, and the overflow flag for signed math. For example, on an x86 you could add two unsigned 64-bit numbers (which we’ll assume are in EDX:EAX and EBX:ECX) something like this: add … Read more

How can I detect integer overflow on 32 bits int?

Math.addExact throws exception on overflow Since Java 8 there is a set of methods in the Math class: toIntExact(long) addExact(int,int) subtractExact(int,int) multiplyExact(int,int) …and versions for long as well. Each of these methods throws ArithmeticException if overflow happens. Otherwise they return the proper result if it fits within the range. Example of addition: int x = … Read more