Convert Bytes to KB, MB, GB, TB, PB, EB- C

size_converter.c

// execution
// gcc size_converter.c -o size_converter && ./size_converter 512 

#include<stdio.h>
#include<stdlib.h>

typedef unsigned long long ULL;


char *types[] = {"Bytes", "KB", "MB", "GB", "TB", "PB", "EB"};
int typesLen = (sizeof(types) / sizeof(types[0]));

ULL pow1024(int power) {
    ULL result = 1024ULL;
    for (int i = 2; i <= power; ++i) result *= 1024ULL;
    return result;
}

// This function converts bytes to its category
// Example: converts 1024 bytes to 1 KB
//
// Parameters:
//   str: converter value: maximum of 13 characters
//   size: in bytes
//

void getSize(char* str, ULL size) {
    int typeIndex = 0;
    ULL bytesDiv = 1ULL;
    for (int i = typesLen - 1; i >= 0; --i) {
        bytesDiv = (ULL) pow1024(i);
        if (size >= bytesDiv) {
            typeIndex = i;
            break;
        }
    }
    sprintf(str, "%.2f %s", (double) size / bytesDiv, types[typeIndex]);
}

int main(int argc, char *argv[]) {
    char str[13];
    for (int i = 1; i < argc; ++i) {
        ULL input = strtoull(argv[i], NULL, 10);
        getSize(str, input);
        printf("%llu -> %s \n", input, str);
    }
}