| /* vi: set sw=4 ts=4: */ |
| /* |
| * June 30, 2001 Manuel Novoa III |
| * |
| * All-integer version (hey, not everyone has floating point) of |
| * make_human_readable_str, modified from similar code I had written |
| * for busybox several months ago. |
| * |
| * Notes: |
| * 1) I'm using an unsigned long long to hold the product size * block_size, |
| * as df (which calls this routine) could request a representation of a |
| * partition size in bytes > max of unsigned long. If long longs aren't |
| * available, it would be possible to do what's needed using polynomial |
| * representations (say, powers of 1024) and manipulating coefficients. |
| * The base ten "bytes" output could be handled similarly. |
| * |
| * 2) This routine always outputs a decimal point and a tenths digit when |
| * display_unit != 0. Hence, it isn't uncommon for the returned string |
| * to have a length of 5 or 6. |
| * |
| * It might be nice to add a flag to indicate no decimal digits in |
| * that case. This could be either an additional parameter, or a |
| * special value of display_unit. Such a flag would also be nice for du. |
| * |
| * Some code to omit the decimal point and tenths digit is sketched out |
| * and "#if 0"'d below. |
| */ |
| |
| #include "libbb.h" |
| |
| const char *make_human_readable_str(unsigned long long size, |
| unsigned long block_size, unsigned long display_unit) |
| { |
| /* The code will adjust for additional (appended) units. */ |
| static const char zero_and_units[] = { '0', 0, 'k', 'M', 'G', 'T' }; |
| static const char fmt[] = "%llu"; |
| static const char fmt_tenths[] = "%llu.%d%c"; |
| |
| static char str[21]; /* Sufficient for 64 bit unsigned integers. */ |
| |
| unsigned long long val; |
| int frac; |
| const char *u; |
| const char *f; |
| |
| u = zero_and_units; |
| f = fmt; |
| frac = 0; |
| |
| val = size * block_size; |
| if (val == 0) { |
| return u; |
| } |
| |
| if (display_unit) { |
| val += display_unit/2; /* Deal with rounding. */ |
| val /= display_unit; /* Don't combine with the line above!!! */ |
| } else { |
| ++u; |
| while ((val >= 1024) |
| && (u < zero_and_units + sizeof(zero_and_units) - 1) |
| ) { |
| f = fmt_tenths; |
| ++u; |
| frac = (((int)(val % 1024)) * 10 + 1024/2) / 1024; |
| val /= 1024; |
| } |
| if (frac >= 10) { /* We need to round up here. */ |
| ++val; |
| frac = 0; |
| } |
| #if 0 |
| /* Sample code to omit decimal point and tenths digit. */ |
| if (/* no_tenths */ 1) { |
| if (frac >= 5) { |
| ++val; |
| } |
| f = "%llu%*c" /* fmt_no_tenths */ ; |
| frac = 1; |
| } |
| #endif |
| } |
| |
| /* If f==fmt then 'frac' and 'u' are ignored. */ |
| snprintf(str, sizeof(str), f, val, frac, *u); |
| |
| return str; |
| } |