From: Paul Eggert Date: Sun, 27 Feb 2000 17:52:01 +0000 (+0000) Subject: Initial revision X-Git-Url: https://git.dogcows.com/gitweb?a=commitdiff_plain;h=a9d7ae22a881292a32293688c10513bddcedd225;p=chaz%2Ftar Initial revision --- diff --git a/lib/human.c b/lib/human.c new file mode 100644 index 0000000..5cfbce9 --- /dev/null +++ b/lib/human.c @@ -0,0 +1,325 @@ +/* human.c -- print human readable file size + Copyright (C) 1996, 1997, 1998, 1999, 2000 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 2, 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, write to the Free Software Foundation, + Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + +/* Originally contributed by lm@sgi.com; + --si, output block size selection, and large file support + added by eggert@twinsun.com. */ + +#if HAVE_CONFIG_H +# include +#endif + +#include +#include + +#if HAVE_LIMITS_H +# include +#endif + +#if HAVE_STRING_H +# include +#else +# include +#endif + +#ifndef CHAR_BIT +# define CHAR_BIT 8 +#endif +#if HAVE_STDLIB_H +# include +#endif + +#ifndef HAVE_DECL_GETENV +"this configure-time declaration test was not run" +#endif +#if !HAVE_DECL_GETENV +char *getenv (); +#endif + +#if ENABLE_NLS +# include +# define _(Text) gettext (Text) +#else +# define _(Text) Text +#endif + +#include +#include +#include + +#include "human.h" + +static const char suffixes[] = +{ + 0, /* not used */ + 'k', /* kilo */ + 'M', /* Mega */ + 'G', /* Giga */ + 'T', /* Tera */ + 'P', /* Peta */ + 'E', /* Exa */ + 'Z', /* Zetta */ + 'Y' /* Yotta */ +}; + +/* Like human_readable_inexact, except always round to even. */ +char * +human_readable (uintmax_t n, char *buf, + int from_block_size, int output_block_size) +{ + return human_readable_inexact (n, buf, from_block_size, output_block_size, + human_round_to_even); +} + +/* Convert N to a human readable format in BUF. + + N is expressed in units of FROM_BLOCK_SIZE. FROM_BLOCK_SIZE must + be nonnegative. + + If OUTPUT_BLOCK_SIZE is positive, use units of OUTPUT_BLOCK_SIZE in + the output number. OUTPUT_BLOCK_SIZE must be a multiple of + FROM_BLOCK_SIZE or vice versa. + + Use INEXACT_STYLE to determine whether to take the ceiling or floor + of any result that cannot be expressed exactly. + + If OUTPUT_BLOCK_SIZE is negative, use a format like "127k" if + possible, using powers of -OUTPUT_BLOCK_SIZE; otherwise, use + ordinary decimal format. Normally -OUTPUT_BLOCK_SIZE is either + 1000 or 1024; it must be at least 2. Most people visually process + strings of 3-4 digits effectively, but longer strings of digits are + more prone to misinterpretation. Hence, converting to an + abbreviated form usually improves readability. Use a suffix + indicating which power is being used. For example, assuming + -OUTPUT_BLOCK_SIZE is 1024, 8500 would be converted to 8.3k, + 133456345 to 127M, 56990456345 to 53G, and so on. Numbers smaller + than -OUTPUT_BLOCK_SIZE aren't modified. */ + +char * +human_readable_inexact (uintmax_t n, char *buf, + int from_block_size, int output_block_size, + enum human_inexact_style inexact_style) +{ + uintmax_t amt; + int base; + int to_block_size; + int tenths = 0; + int power; + char *p; + + /* 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 = 0; + + if (output_block_size < 0) + { + base = -output_block_size; + to_block_size = 1; + } + else + { + base = 0; + to_block_size = output_block_size; + } + + p = buf + LONGEST_HUMAN_READABLE; + *p = '\0'; + +#ifdef lint + /* Suppress `used before initialized' warning. */ + power = 0; +#endif + + /* Adjust AMT out of FROM_BLOCK_SIZE units and into TO_BLOCK_SIZE units. */ + + if (to_block_size <= from_block_size) + { + int multiplier = from_block_size / to_block_size; + amt = n * multiplier; + + if (amt / multiplier != n) + { + /* Overflow occurred during multiplication. We should use + multiple precision arithmetic here, but we'll be lazy and + resort to floating point. This can yield answers that + are slightly off. In practice it is quite rare to + overflow uintmax_t, so this is good enough for now. */ + + double damt = n * (double) multiplier; + + if (! base) + sprintf (buf, "%.0f", damt); + else + { + double e = 1; + power = 0; + + do + { + e *= base; + power++; + } + while (e * base <= damt && power < sizeof suffixes - 1); + + damt /= e; + + sprintf (buf, "%.1f%c", damt, suffixes[power]); + if (4 < strlen (buf)) + sprintf (buf, "%.0f%c", damt, suffixes[power]); + } + + return buf; + } + } + else if (from_block_size == 0) + amt = 0; + else + { + int divisor = to_block_size / from_block_size; + int r10 = (n % divisor) * 10; + int r2 = (r10 % divisor) * 2; + amt = n / divisor; + tenths = r10 / divisor; + rounding = r2 < divisor ? 0 < r2 : 2 + (divisor < r2); + } + + + /* Use power of BASE notation if adjusted AMT is large enough. */ + + if (base && base <= amt) + { + power = 0; + + do + { + int r10 = (amt % base) * 10 + tenths; + int r2 = (r10 % base) * 2 + (rounding >> 1); + amt /= base; + tenths = r10 / base; + rounding = (r2 < base + ? 0 < r2 + rounding + : 2 + (base < r2 + rounding)); + power++; + } + while (base <= amt && power < sizeof suffixes - 1); + + *--p = suffixes[power]; + + if (amt < 10) + { + if (2 * (1 - (int) inexact_style) + < rounding + (tenths & (inexact_style == human_round_to_even))) + { + tenths++; + rounding = 0; + + if (tenths == 10) + { + amt++; + tenths = 0; + } + } + + if (amt < 10) + { + *--p = '0' + tenths; + *--p = '.'; + tenths = rounding = 0; + } + } + } + + if (inexact_style == human_ceiling + ? 0 < tenths + rounding + : inexact_style == human_round_to_even + ? 5 < tenths + (2 < rounding + (amt & 1)) + : /* inexact_style == human_floor */ 0) + { + amt++; + + if (amt == base && power < sizeof suffixes - 1) + { + *p = suffixes[power + 1]; + *--p = '0'; + *--p = '.'; + amt = 1; + } + } + + do + *--p = '0' + (int) (amt % 10); + while ((amt /= 10) != 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_types[] = { -1024, -1000 }; + +static int +default_block_size (void) +{ + return getenv ("POSIXLY_CORRECT") ? 512 : DEFAULT_BLOCK_SIZE; +} + +static strtol_error +humblock (char const *spec, int *block_size) +{ + int i; + + if (! spec && ! (spec = getenv ("BLOCK_SIZE"))) + *block_size = default_block_size (); + else if (0 <= (i = ARGMATCH (spec, block_size_args, block_size_types))) + *block_size = block_size_types[i]; + else + { + char *ptr; + unsigned long val; + strtol_error e = xstrtoul (spec, &ptr, 0, &val, "eEgGkKmMpPtTyYzZ0"); + if (e != LONGINT_OK) + return e; + if (*ptr) + return LONGINT_INVALID_SUFFIX_CHAR; + if ((int) val < 0 || val != (int) val) + return LONGINT_OVERFLOW; + *block_size = (int) val; + } + + return LONGINT_OK; +} + +void +human_block_size (char const *spec, int report_errors, int *block_size) +{ + strtol_error e = humblock (spec, block_size); + if (*block_size == 0) + { + *block_size = default_block_size (); + e = LONGINT_INVALID; + } + if (e != LONGINT_OK && report_errors) + STRTOL_FATAL_ERROR (spec, _("block size"), e); +}