1 /* human.c -- print human readable file size
3 Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002 Free Software
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software Foundation,
18 Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
20 /* Originally contributed by lm@sgi.com;
21 --si, output block size selection, and large file support
22 added by eggert@twinsun.com. */
28 #include <sys/types.h>
48 #ifndef HAVE_DECL_GETENV
49 "this configure-time declaration test was not run"
56 #define _(msgid) gettext (msgid)
64 static const char suffixes[] =
67 'K', /* kibi ('k' for kilo is a special case) */
68 'M', /* mega or mebi */
69 'G', /* giga or gibi */
70 'T', /* tera or tebi */
71 'P', /* peta or pebi */
72 'E', /* exa or exbi */
73 'Z', /* zetta or 2**70 */
74 'Y' /* yotta or 2**80 */
77 /* Generate into P[-1] (and possibly P[-2]) the proper suffix for
78 POWER and BASE. Return the address of the generated suffix. */
80 generate_suffix_backwards (char *p, int power, int base)
82 char letter = suffixes[power];
95 /* If INEXACT_STYLE is not human_round_to_even, and if easily
96 possible, adjust VALUE according to the style. */
98 adjust_value (enum human_inexact_style inexact_style, double value)
100 /* Do not use the floor or ceil functions, as that would mean
101 linking with the standard math library, which is a porting pain.
102 So leave the value alone if it is too large to easily round. */
103 if (inexact_style != human_round_to_even && value < (uintmax_t) -1)
106 value = u + (inexact_style == human_ceiling && u != value);
112 /* Like human_readable_inexact, except always round to even. */
114 human_readable (uintmax_t n, char *buf,
115 int from_block_size, int output_block_size)
117 return human_readable_inexact (n, buf, from_block_size, output_block_size,
118 human_round_to_even);
121 /* Convert N to a human readable format in BUF.
123 N is expressed in units of FROM_BLOCK_SIZE. FROM_BLOCK_SIZE must
126 OUTPUT_BLOCK_SIZE must be nonzero. If it is positive, use units of
127 OUTPUT_BLOCK_SIZE in the output number.
129 Use INEXACT_STYLE to determine whether to take the ceiling or floor
130 of any result that cannot be expressed exactly.
132 If OUTPUT_BLOCK_SIZE is negative, use a format like "127K" if
133 possible, using powers of -OUTPUT_BLOCK_SIZE; otherwise, use
134 ordinary decimal format. Normally -OUTPUT_BLOCK_SIZE is either
135 1000 or 1024; it must be at least 2. Most people visually process
136 strings of 3-4 digits effectively, but longer strings of digits are
137 more prone to misinterpretation. Hence, converting to an
138 abbreviated form usually improves readability. Use a suffix
139 indicating which power is being used. For example, assuming
140 -OUTPUT_BLOCK_SIZE is 1024, 8500 would be converted to 8.3K,
141 133456345 to 127M, 56990456345 to 53G, and so on. Numbers smaller
142 than -OUTPUT_BLOCK_SIZE aren't modified. If -OUTPUT_BLOCK_SIZE is
143 1024, append a "B" after any size letter. */
146 human_readable_inexact (uintmax_t n, char *buf,
147 int from_block_size, int output_block_size,
148 enum human_inexact_style inexact_style)
157 /* 0 means adjusted N == AMT.TENTHS;
158 1 means AMT.TENTHS < adjusted N < AMT.TENTHS + 0.05;
159 2 means adjusted N == AMT.TENTHS + 0.05;
160 3 means AMT.TENTHS + 0.05 < adjusted N < AMT.TENTHS + 0.1. */
163 if (output_block_size < 0)
165 base = -output_block_size;
171 to_block_size = output_block_size;
174 p = buf + LONGEST_HUMAN_READABLE;
178 /* Suppress `used before initialized' warning. */
182 /* Adjust AMT out of FROM_BLOCK_SIZE units and into TO_BLOCK_SIZE units. */
189 if (to_block_size <= from_block_size
190 ? (from_block_size % to_block_size != 0
191 || (multiplier = from_block_size / to_block_size,
192 (amt = n * multiplier) / multiplier != n))
193 : (from_block_size == 0
194 || to_block_size % from_block_size != 0
195 || (divisor = to_block_size / from_block_size,
196 r10 = (n % divisor) * 10,
197 r2 = (r10 % divisor) * 2,
199 tenths = r10 / divisor,
200 rounding = r2 < divisor ? 0 < r2 : 2 + (divisor < r2),
203 /* Either the result cannot be computed easily using uintmax_t,
204 or from_block_size is zero. Fall back on floating point.
205 FIXME: This can yield answers that are slightly off. */
207 double damt = n * (from_block_size / (double) to_block_size);
210 sprintf (buf, "%.0f", adjust_value (inexact_style, damt));
223 while (e * base <= damt && power < sizeof suffixes - 1);
228 psuffix = generate_suffix_backwards (suffix + 2, power, base);
229 sprintf (buf, "%.1f%s",
230 adjust_value (inexact_style, damt), psuffix);
231 if (4 + (base == 1000) < strlen (buf))
232 sprintf (buf, "%.0f%s",
233 adjust_value (inexact_style, damt * 10) / 10, psuffix);
240 /* Use power of BASE notation if adjusted AMT is large enough. */
242 if (base && base <= amt)
248 int r10 = (amt % base) * 10 + tenths;
249 int r2 = (r10 % base) * 2 + (rounding >> 1);
252 rounding = (r2 < base
254 : 2 + (base < r2 + rounding));
257 while (base <= amt && power < sizeof suffixes - 1);
259 p = generate_suffix_backwards (p, power, base);
263 if (2 * (1 - (int) inexact_style)
264 < rounding + (tenths & (inexact_style == human_round_to_even)))
280 tenths = rounding = 0;
285 if (inexact_style == human_ceiling
286 ? 0 < tenths + rounding
287 : inexact_style == human_round_to_even
288 ? 5 < tenths + (2 < rounding + (amt & 1))
289 : /* inexact_style == human_floor */ 0)
293 if (amt == base && power < sizeof suffixes - 1)
295 *p = suffixes[power + 1];
303 *--p = '0' + (int) (amt % 10);
304 while ((amt /= 10) != 0);
310 /* The default block size used for output. This number may change in
311 the future as disks get larger. */
312 #ifndef DEFAULT_BLOCK_SIZE
313 # define DEFAULT_BLOCK_SIZE 1024
316 static char const *const block_size_args[] = { "human-readable", "si", 0 };
317 static int const block_size_types[] = { -1024, -1000 };
320 default_block_size (void)
322 return getenv ("POSIXLY_CORRECT") ? 512 : DEFAULT_BLOCK_SIZE;
326 humblock (char const *spec, int *block_size)
330 if (! spec && ! (spec = getenv ("BLOCK_SIZE")))
331 *block_size = default_block_size ();
332 else if (0 <= (i = ARGMATCH (spec, block_size_args, block_size_types)))
333 *block_size = block_size_types[i];
338 strtol_error e = xstrtoul (spec, &ptr, 0, &val, "eEgGkKmMpPtTyYzZ0");
342 return LONGINT_INVALID_SUFFIX_CHAR;
343 if ((int) val < 0 || val != (int) val)
344 return LONGINT_OVERFLOW;
345 *block_size = (int) val;
352 human_block_size (char const *spec, int report_errors, int *block_size)
354 strtol_error e = humblock (spec, block_size);
355 if (*block_size == 0)
357 *block_size = default_block_size ();
360 if (e != LONGINT_OK && report_errors)
361 STRTOL_FATAL_ERROR (spec, _("block size"), e);