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freebsd-dev/contrib/tar/lib/human.c

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/* 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 <config.h>
#endif
#include <sys/types.h>
#include <stdio.h>
#if HAVE_LIMITS_H
# include <limits.h>
#endif
#if HAVE_STRING_H
# include <string.h>
#else
# include <strings.h>
#endif
#ifndef CHAR_BIT
# define CHAR_BIT 8
#endif
#if HAVE_STDLIB_H
# include <stdlib.h>
#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 <libintl.h>
# define _(Text) gettext (Text)
#else
# define _(Text) Text
#endif
#include <argmatch.h>
#include <error.h>
#include <xstrtol.h>
#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 */
};
/* If INEXACT_STYLE is not human_round_to_even, and if easily
possible, adjust VALUE according to the style. */
static double
adjust_value (enum human_inexact_style inexact_style, double value)
{
/* Do not use the floor or ceil functions, as that would mean
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_even && value < (uintmax_t) -1)
{
uintmax_t u = value;
value = u + (inexact_style == human_ceiling && u != value);
}
return value;
}
/* 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.
OUTPUT_BLOCK_SIZE must be nonzero. If it is positive, use units of
OUTPUT_BLOCK_SIZE in the output number.
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. */
{
int multiplier;
int divisor;
int r2;
int r10;
if (to_block_size <= from_block_size
? (from_block_size % to_block_size != 0
|| (multiplier = from_block_size / to_block_size,
(amt = n * multiplier) / multiplier != n))
: (from_block_size == 0
|| to_block_size % from_block_size != 0
|| (divisor = to_block_size / from_block_size,
r10 = (n % divisor) * 10,
r2 = (r10 % divisor) * 2,
amt = n / divisor,
tenths = r10 / divisor,
rounding = r2 < divisor ? 0 < r2 : 2 + (divisor < r2),
0)))
{
/* 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. */
double damt = n * (from_block_size / (double) to_block_size);
if (! base)
sprintf (buf, "%.0f", adjust_value (inexact_style, 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", adjust_value (inexact_style, damt),
suffixes[power]);
if (4 < strlen (buf))
sprintf (buf, "%.0f%c",
adjust_value (inexact_style, damt * 10) / 10,
suffixes[power]);
}
return buf;
}
}
/* 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);
}
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