#include <stdio.h>#include <stdlib.h>#include <string.h>#define SECTOR_SIZE_DEFAULT   512LL#define KILOBYTE_SIZE 1000LL#define MEGABYTE_SIZE 1000000LL#define GIGABYTE_SIZE 1000000000LL#define TERABYTE_SIZE 1000000000000LL#define KIBIBYTE_SIZE 1024LL#define MEBIBYTE_SIZE 1048576LL#define GIBIBYTE_SIZE 1073741824LL#define TEBIBYTE_SIZE 1099511627776LLtypedef enum{    BASE_BINARY,    BASE_DECIMAL} Base;typedef enum {    DIGIT_UNIT_BYTE,    DIGIT_UNIT_KILOBYTE,    DIGIT_UNIT_MEGABYTE,    DIGIT_UNIT_GIGABYTE,    DIGIT_UNIT_TERABYTE,    DIGIT_UNIT_KIBIBYTE,    DIGIT_UNIT_MEBIBYTE,    DIGIT_UNIT_GIBIBYTE,    DIGIT_UNIT_TEBIBYTE} DigitUnit;char *unit_format_custom (long long n, DigitUnit unit){    char *str = malloc(64);    memset (str, 0, 64);    float f;    int len;    char *suffix;        switch (unit)    {    case DIGIT_UNIT_BYTE:    {        sprintf (str, "%lld%s", n, "B");        break;    }    case DIGIT_UNIT_KILOBYTE:    {        f = (float) n / KILOBYTE_SIZE;        sprintf (str, "%.1f", f);        len = strlen(str);        suffix = (*(str + (len - 1)) == ‘0‘) ? str + len - 2 : str + len;        memset (suffix, 0, 2);        sprintf (suffix, "%s", "K");        break;    }    case DIGIT_UNIT_MEGABYTE:    {        f = (float) n / MEGABYTE_SIZE;        sprintf (str, "%.1f", f);        len = strlen(str);        suffix = (*(str + (len - 1)) == ‘0‘) ? str + len - 2 : str + len;        memset (suffix, 0, 2);        sprintf (suffix, "%s", "M");        break;    }    case DIGIT_UNIT_GIGABYTE:    {        f = (float) n / GIGABYTE_SIZE;        sprintf (str, "%.1f", f);        len = strlen(str);        suffix = (*(str + (len - 1)) == ‘0‘) ? str + len - 2 : str + len;        memset (suffix, 0, 2);        sprintf (suffix, "%s", "G");        break;    }    case DIGIT_UNIT_TERABYTE:    {        f = (float) n / TERABYTE_SIZE;        sprintf (str, "%.1f", f);        len = strlen(str);        suffix = (*(str + (len - 1)) == ‘0‘) ? str + len - 2 : str + len;        memset (suffix, 0, 2);        sprintf (suffix, "%s", "T");        break;    }    case DIGIT_UNIT_KIBIBYTE:    {        f = (float) n / KIBIBYTE_SIZE;        sprintf (str, "%.1f", f);        len = strlen(str);        suffix = (*(str + (len - 1)) == ‘0‘) ? str + len - 2 : str + len;        memset (suffix, 0, 2);        sprintf (suffix, "%s", "Ki");        break;    }    case DIGIT_UNIT_MEBIBYTE:    {        f = (float) n / MEBIBYTE_SIZE;        sprintf (str, "%.1f", f);        len = strlen(str);        suffix = (*(str + (len - 1)) == ‘0‘) ? str + len - 2 : str + len;        memset (suffix, 0, 2);        sprintf (suffix, "%s", "Mi");        break;    }    case DIGIT_UNIT_GIBIBYTE:    {        f = (float) n / GIBIBYTE_SIZE;        sprintf (str, "%.1f", f);        len = strlen(str);        suffix = (*(str + (len - 1)) == ‘0‘) ? str + len - 2 : str + len;        memset (suffix, 0, 2);        sprintf (suffix, "%s", "Gi");        break;    }    case DIGIT_UNIT_TEBIBYTE:    {        f = (float) n / TEBIBYTE_SIZE;        sprintf (str, "%.1f", f);        len = strlen(str);        suffix = (*(str + (len - 1)) == ‘0‘) ? str + len - 2 : str + len;        memset (suffix, 0, 2);        sprintf (suffix, "%s", "Ti");        break;    }    }    return str;}static char *unit_format (long long n, Base base){    DigitUnit unit = DIGIT_UNIT_BYTE - 1;    long long tmp = n;    if (base == BASE_DECIMAL)    {        while (tmp > 0)        {            tmp /= 1000;            unit++;        }    }    else if (base == BASE_BINARY)    {        while (tmp > 0)        {            tmp /= 1024;            unit++;            if (unit == DIGIT_UNIT_KILOBYTE)            {                unit = DIGIT_UNIT_KIBIBYTE;            }        }    }    return unit_format_custom (n, unit);}int main(int argc, char **argv){    printf ("%s\n", unit_format_custom (25678, DIGIT_UNIT_KILOBYTE));    printf ("%s\n", unit_format (4096, BASE_BINARY));    printf ("%s\n", unit_format (4096, BASE_DECIMAL));    printf ("%s\n", unit_format (8192, BASE_BINARY));    printf ("%s\n", unit_format (8192, BASE_DECIMAL));    return 0;}