source: branches/2.2.2/mindi-busybox/libbb/human_readable.c @ 1247

Last change on this file since 1247 was 821, checked in by Bruno Cornec, 14 years ago

Addition of busybox 1.2.1 as a mindi-busybox new package
This should avoid delivering binary files in mindi not built there (Fedora and Debian are quite serious about that)

File size: 2.5 KB
Line 
1/*
2 * June 30, 2001                 Manuel Novoa III
3 *
4 * All-integer version (hey, not everyone has floating point) of
5 * make_human_readable_str, modified from similar code I had written
6 * for busybox several months ago.
7 *
8 * Notes:
9 *   1) I'm using an unsigned long long to hold the product size * block_size,
10 *      as df (which calls this routine) could request a representation of a
11 *      partition size in bytes > max of unsigned long.  If long longs aren't
12 *      available, it would be possible to do what's needed using polynomial
13 *      representations (say, powers of 1024) and manipulating coefficients.
14 *      The base ten "bytes" output could be handled similarly.
15 *
16 *   2) This routine always outputs a decimal point and a tenths digit when
17 *      display_unit != 0.  Hence, it isn't uncommon for the returned string
18 *      to have a length of 5 or 6.
19 *
20 *      It might be nice to add a flag to indicate no decimal digits in
21 *      that case.  This could be either an additional parameter, or a
22 *      special value of display_unit.  Such a flag would also be nice for du.
23 *
24 *      Some code to omit the decimal point and tenths digit is sketched out
25 *      and "#if 0"'d below.
26 */
27
28#include <stdio.h>
29#include "libbb.h"
30
31const char *make_human_readable_str(unsigned long long size,
32    unsigned long block_size, unsigned long display_unit)
33{
34    /* The code will adjust for additional (appended) units. */
35    static const char zero_and_units[] = { '0', 0, 'k', 'M', 'G', 'T' };
36    static const char fmt[] = "%llu";
37    static const char fmt_tenths[] = "%llu.%d%c";
38
39    static char str[21];        /* Sufficient for 64 bit unsigned integers. */
40
41    unsigned long long val;
42    int frac;
43    const char *u;
44    const char *f;
45
46    u = zero_and_units;
47    f = fmt;
48    frac = 0;
49
50    val = size * block_size;
51    if (val == 0) {
52        return u;
53    }
54
55    if (display_unit) {
56        val += display_unit/2;  /* Deal with rounding. */
57        val /= display_unit;    /* Don't combine with the line above!!! */
58    } else {
59        ++u;
60        while ((val >= KILOBYTE)
61               && (u < zero_and_units + sizeof(zero_and_units) - 1)) {
62            f = fmt_tenths;
63            ++u;
64            frac = ((((int)(val % KILOBYTE)) * 10) + (KILOBYTE/2)) / KILOBYTE;
65            val /= KILOBYTE;
66        }
67        if (frac >= 10) {       /* We need to round up here. */
68            ++val;
69            frac = 0;
70        }
71#if 0
72        /* Sample code to omit decimal point and tenths digit. */
73        if ( /* no_tenths */ 1 ) {
74            if ( frac >= 5 ) {
75                ++val;
76            }
77            f = "%llu%*c" /* fmt_no_tenths */ ;
78            frac = 1;
79        }
80#endif
81    }
82
83    /* If f==fmt then 'frac' and 'u' are ignored. */
84    snprintf(str, sizeof(str), f, val, frac, *u);
85
86    return str;
87}
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