CODEWITHSUNDEEP
csystemmemory-address
Algorisum
Algorisum

Reputation: 11

How to check the condition of individual bytes stored in an address?

#include <stdio.h>

int main(){

int x = 2271560481; // 0x87654321

for (size_t i = 0; i < sizeof(x); ++i) {

unsigned char byte = *((unsigned char *)&x + i);


printf("Byte %d = %u\n", i, (unsigned)byte);
}


return 0;

}

For example I have this code right here displaying an output of :

Byte 0 = 33
Byte 1 = 67
Byte 2 = 101
Byte 3 = 135

How do I check the condition to see if the value is stored in the address?

Upvotes: 0

Views: 141

Answers (2)

pm100
pm100

Reputation: 50180

Your code is loading one byte at a time into byte , its not a pointer so you cannot index off it. Do

unsigned char *bytePtr = ((unsigned char *)&x);

for (size_t i = 0; i < sizeof(x); ++i) {
printf("Byte %d = %u\n", i, bytePtr[i]);
}

now you can do your test function using bytePtr

Upvotes: 2

kiran Biradar
kiran Biradar

Reputation: 12732

Your byte will hold last value. If you want to store all the values you need array. Consider below example. 

  #include <stdio.h>

    int main(){

    int x = 2271560481; // 0x87654321
    size_t i =0;
    unsigned char byte[sizeof x];
    for (i = 0; i < sizeof(x); ++i) {

        byte[i] = *((unsigned char *)&x + i);

        printf("Byte %d = %u\n", i, (unsigned)byte[i]);
      }

      if (byte[0] == 33 && byte[1] == 67 && byte[2] == 101 && byte[3] == 135) 
      {
        return 1;
      }
      return 0;
    }

Upvotes: 0

Related Questions