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Diffstat (limited to 'lib/human.c')
| -rw-r--r-- | lib/human.c | 473 |
1 files changed, 473 insertions, 0 deletions
diff --git a/lib/human.c b/lib/human.c new file mode 100644 index 0000000..b96ddee --- /dev/null +++ b/lib/human.c @@ -0,0 +1,473 @@ +/* human.c -- print human readable file size + + Copyright (C) 1996-2007, 2009-2023 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. */ + +/* Written by Paul Eggert and Larry McVoy. */ + +#include <config.h> + +#include "human.h" + +#include <locale.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include <argmatch.h> +#include <error.h> +#include <intprops.h> + +/* The maximum length of a suffix like "KiB". */ +#define HUMAN_READABLE_SUFFIX_LENGTH_MAX 3 + +static const char power_letter[] = +{ + 0, /* not used */ + 'K', /* kibi ('k' for kilo is a special case) */ + 'M', /* mega or mebi */ + 'G', /* giga or gibi */ + 'T', /* tera or tebi */ + 'P', /* peta or pebi */ + 'E', /* exa or exbi */ + 'Z', /* zetta or 2**70 */ + 'Y', /* yotta or 2**80 */ + 'R', /* ronna or 2**90 */ + 'Q' /* quetta or 2**100 */ +}; + + +/* If INEXACT_STYLE is not human_round_to_nearest, and if easily + possible, adjust VALUE according to the style. */ + +static long double +adjust_value (int inexact_style, long double value) +{ + /* Do not use the floorl or ceill functions, as that would mean + checking for their presence and possibly linking with the + standard math library, which is a porting pain. So leave the + value alone if it is too large to easily round. */ + if (inexact_style != human_round_to_nearest && value < UINTMAX_MAX) + { + uintmax_t u = value; + value = u + (inexact_style == human_ceiling && u != value); + } + + return value; +} + +/* Group the digits of NUMBER according to the grouping rules of the + current locale. NUMBER contains NUMBERLEN digits. Modify the + bytes pointed to by NUMBER in place, subtracting 1 from NUMBER for + each byte inserted. Return the starting address of the modified + number. + + To group the digits, use GROUPING and THOUSANDS_SEP as in 'struct + lconv' from <locale.h>. */ + +static char * +group_number (char *number, size_t numberlen, + char const *grouping, char const *thousands_sep) +{ + register char *d; + size_t grouplen = SIZE_MAX; + size_t thousands_seplen = strlen (thousands_sep); + size_t i = numberlen; + + /* The maximum possible value for NUMBERLEN is the number of digits + in the square of the largest uintmax_t, so double the size needed. */ + char buf[2 * INT_STRLEN_BOUND (uintmax_t) + 1]; + + memcpy (buf, number, numberlen); + d = number + numberlen; + + for (;;) + { + unsigned char g = *grouping; + + if (g) + { + grouplen = g < CHAR_MAX ? g : i; + grouping++; + } + + if (i < grouplen) + grouplen = i; + + d -= grouplen; + i -= grouplen; + memcpy (d, buf + i, grouplen); + if (i == 0) + return d; + + d -= thousands_seplen; + memcpy (d, thousands_sep, thousands_seplen); + } +} + +/* Convert N to a human readable format in BUF, using the options OPTS. + + N is expressed in units of FROM_BLOCK_SIZE. FROM_BLOCK_SIZE must + be nonnegative. + + Use units of TO_BLOCK_SIZE in the output number. TO_BLOCK_SIZE + must be positive. + + Use (OPTS & (human_round_to_nearest | human_floor | human_ceiling)) + to determine whether to take the ceiling or floor of any result + that cannot be expressed exactly. + + If (OPTS & human_group_digits), group the thousands digits + according to the locale, e.g., "1,000,000" in an American English + locale. + + If (OPTS & human_autoscale), deduce the output block size + automatically; TO_BLOCK_SIZE must be 1 but it has no effect on the + output. Use powers of 1024 if (OPTS & human_base_1024), and powers + of 1000 otherwise. For example, assuming powers of 1024, 8500 + would be converted to 8.3, 133456345 to 127, 56990456345 to 53, and + so on. Numbers smaller than the power aren't modified. + human_autoscale is normally used together with human_SI. + + If (OPTS & human_space_before_unit), use a space to separate the + number from any suffix that is appended as described below. + + If (OPTS & human_SI), append an SI prefix indicating which power is + being used. If in addition (OPTS & human_B), append "B" (if base + 1000) or "iB" (if base 1024) to the SI prefix. When ((OPTS & + human_SI) && ! (OPTS & human_autoscale)), TO_BLOCK_SIZE must be a + power of 1024 or of 1000, depending on (OPTS & + human_base_1024). */ + +char * +human_readable (uintmax_t n, char *buf, int opts, + uintmax_t from_block_size, uintmax_t to_block_size) +{ + int inexact_style = + opts & (human_round_to_nearest | human_floor | human_ceiling); + unsigned int base = opts & human_base_1024 ? 1024 : 1000; + uintmax_t amt; + int tenths; + int exponent = -1; + int exponent_max = sizeof power_letter - 1; + char *p; + char *psuffix; + char const *integerlim; + + /* 0 means adjusted N == AMT.TENTHS; + 1 means AMT.TENTHS < adjusted N < AMT.TENTHS + 0.05; + 2 means adjusted N == AMT.TENTHS + 0.05; + 3 means AMT.TENTHS + 0.05 < adjusted N < AMT.TENTHS + 0.1. */ + int rounding; + + char const *decimal_point = "."; + size_t decimal_pointlen = 1; + char const *grouping = ""; + char const *thousands_sep = ""; + struct lconv const *l = localeconv (); + size_t pointlen = strlen (l->decimal_point); + if (0 < pointlen && pointlen <= MB_LEN_MAX) + { + decimal_point = l->decimal_point; + decimal_pointlen = pointlen; + } + grouping = l->grouping; + if (strlen (l->thousands_sep) <= MB_LEN_MAX) + thousands_sep = l->thousands_sep; + + /* Leave room for a trailing space and following suffix. */ + psuffix = buf + LONGEST_HUMAN_READABLE - 1 - HUMAN_READABLE_SUFFIX_LENGTH_MAX; + p = psuffix; + + /* Adjust AMT out of FROM_BLOCK_SIZE units and into TO_BLOCK_SIZE + units. If this can be done exactly with integer arithmetic, do + not use floating point operations. */ + if (to_block_size <= from_block_size) + { + if (from_block_size % to_block_size == 0) + { + uintmax_t multiplier = from_block_size / to_block_size; + amt = n * multiplier; + if (amt / multiplier == n) + { + tenths = 0; + rounding = 0; + goto use_integer_arithmetic; + } + } + } + else if (from_block_size != 0 && to_block_size % from_block_size == 0) + { + uintmax_t divisor = to_block_size / from_block_size; + uintmax_t r10 = (n % divisor) * 10; + uintmax_t r2 = (r10 % divisor) * 2; + amt = n / divisor; + tenths = r10 / divisor; + rounding = r2 < divisor ? 0 < r2 : 2 + (divisor < r2); + goto use_integer_arithmetic; + } + + { + /* Either the result cannot be computed easily using uintmax_t, + or from_block_size is zero. Fall back on floating point. + FIXME: This can yield answers that are slightly off. */ + + long double dto_block_size = to_block_size; + long double damt = n * (from_block_size / dto_block_size); + size_t buflen; + size_t nonintegerlen; + + if (! (opts & human_autoscale)) + { + sprintf (buf, "%.0Lf", adjust_value (inexact_style, damt)); + buflen = strlen (buf); + nonintegerlen = 0; + } + else + { + long double e = 1; + exponent = 0; + + do + { + e *= base; + exponent++; + } + while (e * base <= damt && exponent < exponent_max); + + damt /= e; + + sprintf (buf, "%.1Lf", adjust_value (inexact_style, damt)); + buflen = strlen (buf); + nonintegerlen = decimal_pointlen + 1; + + if (1 + nonintegerlen + ! (opts & human_base_1024) < buflen + || ((opts & human_suppress_point_zero) + && buf[buflen - 1] == '0')) + { + sprintf (buf, "%.0Lf", + adjust_value (inexact_style, damt * 10) / 10); + buflen = strlen (buf); + nonintegerlen = 0; + } + } + + p = psuffix - buflen; + memmove (p, buf, buflen); + integerlim = p + buflen - nonintegerlen; + } + goto do_grouping; + + use_integer_arithmetic: + { + /* The computation can be done exactly, with integer arithmetic. + + Use power of BASE notation if requested and if adjusted AMT is + large enough. */ + + if (opts & human_autoscale) + { + exponent = 0; + + if (base <= amt) + { + do + { + unsigned int r10 = (amt % base) * 10 + tenths; + unsigned int r2 = (r10 % base) * 2 + (rounding >> 1); + amt /= base; + tenths = r10 / base; + rounding = (r2 < base + ? (r2 + rounding) != 0 + : 2 + (base < r2 + rounding)); + exponent++; + } + while (base <= amt && exponent < exponent_max); + + if (amt < 10) + { + if (inexact_style == human_round_to_nearest + ? 2 < rounding + (tenths & 1) + : inexact_style == human_ceiling && 0 < rounding) + { + tenths++; + rounding = 0; + + if (tenths == 10) + { + amt++; + tenths = 0; + } + } + + if (amt < 10 + && (tenths || ! (opts & human_suppress_point_zero))) + { + *--p = '0' + tenths; + p -= decimal_pointlen; + memcpy (p, decimal_point, decimal_pointlen); + tenths = rounding = 0; + } + } + } + } + + if (inexact_style == human_round_to_nearest + ? 5 < tenths + (0 < rounding + (amt & 1)) + : inexact_style == human_ceiling && 0 < tenths + rounding) + { + amt++; + + if ((opts & human_autoscale) + && amt == base && exponent < exponent_max) + { + exponent++; + if (! (opts & human_suppress_point_zero)) + { + *--p = '0'; + p -= decimal_pointlen; + memcpy (p, decimal_point, decimal_pointlen); + } + amt = 1; + } + } + + integerlim = p; + + do + { + int digit = amt % 10; + *--p = digit + '0'; + } + while ((amt /= 10) != 0); + } + + do_grouping: + if (opts & human_group_digits) + p = group_number (p, integerlim - p, grouping, thousands_sep); + + if (opts & human_SI) + { + if (exponent < 0) + { + uintmax_t power; + exponent = 0; + for (power = 1; power < to_block_size; power *= base) + if (++exponent == exponent_max) + break; + } + + if ((exponent | (opts & human_B)) && (opts & human_space_before_unit)) + *psuffix++ = ' '; + + if (exponent) + *psuffix++ = (! (opts & human_base_1024) && exponent == 1 + ? 'k' + : power_letter[exponent]); + + if (opts & human_B) + { + if ((opts & human_base_1024) && exponent) + *psuffix++ = 'i'; + *psuffix++ = 'B'; + } + } + + *psuffix = '\0'; + + return p; +} + + +/* The default block size used for output. This number may change in + the future as disks get larger. */ +#ifndef DEFAULT_BLOCK_SIZE +# define DEFAULT_BLOCK_SIZE 1024 +#endif + +static char const *const block_size_args[] = { "human-readable", "si", 0 }; +static int const block_size_opts[] = + { + human_autoscale + human_SI + human_base_1024, + human_autoscale + human_SI + }; + +static uintmax_t +default_block_size (void) +{ + return getenv ("POSIXLY_CORRECT") ? 512 : DEFAULT_BLOCK_SIZE; +} + +static strtol_error +humblock (char const *spec, uintmax_t *block_size, int *options) +{ + int i; + int opts = 0; + + if (! spec + && ! (spec = getenv ("BLOCK_SIZE")) + && ! (spec = getenv ("BLOCKSIZE"))) + *block_size = default_block_size (); + else + { + if (*spec == '\'') + { + opts |= human_group_digits; + spec++; + } + + if (0 <= (i = ARGMATCH (spec, block_size_args, block_size_opts))) + { + opts |= block_size_opts[i]; + *block_size = 1; + } + else + { + char *ptr; + strtol_error e = xstrtoumax (spec, &ptr, 0, block_size, + "eEgGkKmMpPtTyYzZ0"); + if (e != LONGINT_OK) + { + *options = 0; + return e; + } + for (; ! ('0' <= *spec && *spec <= '9'); spec++) + if (spec == ptr) + { + opts |= human_SI; + if (ptr[-1] == 'B') + opts |= human_B; + if (ptr[-1] != 'B' || ptr[-2] == 'i') + opts |= human_base_1024; + break; + } + } + } + + *options = opts; + return LONGINT_OK; +} + +enum strtol_error +human_options (char const *spec, int *opts, uintmax_t *block_size) +{ + strtol_error e = humblock (spec, block_size, opts); + if (*block_size == 0) + { + *block_size = default_block_size (); + e = LONGINT_INVALID; + } + return e; +} |