Contents of /trunk/mkinitrd-magellan/busybox/libbb/human_readable.c
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Sat Sep 1 22:45:15 2007 UTC (17 years ago) by niro
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Sat Sep 1 22:45:15 2007 UTC (17 years ago) by niro
File MIME type: text/plain
File size: 2593 byte(s)
-import if magellan mkinitrd; it is a fork of redhats mkinitrd-5.0.8 with all magellan patches and features; deprecates magellan-src/mkinitrd
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * June 30, 2001 Manuel Novoa III |
4 | * |
5 | * All-integer version (hey, not everyone has floating point) of |
6 | * make_human_readable_str, modified from similar code I had written |
7 | * for busybox several months ago. |
8 | * |
9 | * Notes: |
10 | * 1) I'm using an unsigned long long to hold the product size * block_size, |
11 | * as df (which calls this routine) could request a representation of a |
12 | * partition size in bytes > max of unsigned long. If long longs aren't |
13 | * available, it would be possible to do what's needed using polynomial |
14 | * representations (say, powers of 1024) and manipulating coefficients. |
15 | * The base ten "bytes" output could be handled similarly. |
16 | * |
17 | * 2) This routine always outputs a decimal point and a tenths digit when |
18 | * display_unit != 0. Hence, it isn't uncommon for the returned string |
19 | * to have a length of 5 or 6. |
20 | * |
21 | * It might be nice to add a flag to indicate no decimal digits in |
22 | * that case. This could be either an additional parameter, or a |
23 | * special value of display_unit. Such a flag would also be nice for du. |
24 | * |
25 | * Some code to omit the decimal point and tenths digit is sketched out |
26 | * and "#if 0"'d below. |
27 | */ |
28 | |
29 | #include <stdio.h> |
30 | #include "libbb.h" |
31 | |
32 | const char *make_human_readable_str(unsigned long long size, |
33 | unsigned long block_size, unsigned long display_unit) |
34 | { |
35 | /* The code will adjust for additional (appended) units. */ |
36 | static const char zero_and_units[] = { '0', 0, 'k', 'M', 'G', 'T' }; |
37 | static const char fmt[] = "%llu"; |
38 | static const char fmt_tenths[] = "%llu.%d%c"; |
39 | |
40 | static char str[21]; /* Sufficient for 64 bit unsigned integers. */ |
41 | |
42 | unsigned long long val; |
43 | int frac; |
44 | const char *u; |
45 | const char *f; |
46 | |
47 | u = zero_and_units; |
48 | f = fmt; |
49 | frac = 0; |
50 | |
51 | val = size * block_size; |
52 | if (val == 0) { |
53 | return u; |
54 | } |
55 | |
56 | if (display_unit) { |
57 | val += display_unit/2; /* Deal with rounding. */ |
58 | val /= display_unit; /* Don't combine with the line above!!! */ |
59 | } else { |
60 | ++u; |
61 | while ((val >= 1024) |
62 | && (u < zero_and_units + sizeof(zero_and_units) - 1) |
63 | ) { |
64 | f = fmt_tenths; |
65 | ++u; |
66 | frac = (((int)(val % 1024)) * 10 + 1024/2) / 1024; |
67 | val /= 1024; |
68 | } |
69 | if (frac >= 10) { /* We need to round up here. */ |
70 | ++val; |
71 | frac = 0; |
72 | } |
73 | #if 0 |
74 | /* Sample code to omit decimal point and tenths digit. */ |
75 | if ( /* no_tenths */ 1 ) { |
76 | if ( frac >= 5 ) { |
77 | ++val; |
78 | } |
79 | f = "%llu%*c" /* fmt_no_tenths */ ; |
80 | frac = 1; |
81 | } |
82 | #endif |
83 | } |
84 | |
85 | /* If f==fmt then 'frac' and 'u' are ignored. */ |
86 | snprintf(str, sizeof(str), f, val, frac, *u); |
87 | |
88 | return str; |
89 | } |