crypto/external/bsd/openssh/dist/fmt_scaled.c

   1 /*      $NetBSD: fmt_scaled.c,v 1.1 2009/02/16 20:53:54 christos Exp $  */
   2 /*      $OpenBSD: fmt_scaled.c,v 1.9 2007/03/20 03:42:52 tedu Exp $     */
   3
   4 /*
   5  * Copyright (c) 2001, 2002, 2003 Ian F. Darwin.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. The name of the author may not be used to endorse or promote products
  16  *    derived from this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  */
  29
  30 /* OPENBSD ORIGINAL: lib/libutil/fmt_scaled.c */
  31
  32 /*
  33  * fmt_scaled: Format numbers scaled for human comprehension
  34  * scan_scaled: Scan numbers in this format.
  35  *
  36  * "Human-readable" output uses 4 digits max, and puts a unit suffix at
  37  * the end.  Makes output compact and easy-to-read esp. on huge disks.
  38  * Formatting code was originally in OpenBSD "df", converted to library routine.
  39  * Scanning code written for OpenBSD libutil.
  40  */
  41
  42 #include "includes.h"
  43 __RCSID("$NetBSD: fmt_scaled.c,v 1.1 2009/02/16 20:53:54 christos Exp $");
  44
  45 #ifndef HAVE_FMT_SCALED
  46
  47 #include <stdio.h>
  48 #include <stdlib.h>
  49 #include <errno.h>
  50 #include <string.h>
  51 #include <ctype.h>
  52 #include <limits.h>
  53
  54 #include "fmt_scaled.h"
  55
  56 typedef enum {
  57         NONE = 0, KILO = 1, MEGA = 2, GIGA = 3, TERA = 4, PETA = 5, EXA = 6
  58 } unit_type;
  59
  60 /* These three arrays MUST be in sync!  XXX make a struct */
  61 static unit_type units[] = { NONE, KILO, MEGA, GIGA, TERA, PETA, EXA };
  62 static char scale_chars[] = "BKMGTPE";
  63 static long long scale_factors[] = {
  64         1LL,
  65         1024LL,
  66         1024LL*1024,
  67         1024LL*1024*1024,
  68         1024LL*1024*1024*1024,
  69         1024LL*1024*1024*1024*1024,
  70         1024LL*1024*1024*1024*1024*1024,
  71 };
  72 #define SCALE_LENGTH (sizeof(units)/sizeof(units[0]))
  73
  74 #define MAX_DIGITS (SCALE_LENGTH * 3)   /* XXX strlen(sprintf("%lld", -1)? */
  75
  76 #ifdef notdef
  77 /** Convert the given input string "scaled" into numeric in "result".
  78  * Return 0 on success, -1 and errno set on error.
  79  */
  80 scan_scaled(char *scaled, long long *result)
  81 {
  82         char *p = scaled;
  83         int sign = 0;
  84         unsigned int i, ndigits = 0, fract_digits = 0;
  85         long long scale_fact = 1, whole = 0, fpart = 0;
  86
  87         /* Skip leading whitespace */
  88         while (isascii((unsigned char)*p) && isspace((unsigned char)*p))
  89                 ++p;
  90
  91         /* Then at most one leading + or - */
  92         while (*p == '-' || *p == '+') {
  93                 if (*p == '-') {
  94                         if (sign) {
  95                                 errno = EINVAL;
  96                                 return -1;
  97                         }
  98                         sign = -1;
  99                         ++p;
 100                 } else if (*p == '+') {
 101                         if (sign) {
 102                                 errno = EINVAL;
 103                                 return -1;
 104                         }
 105                         sign = +1;
 106                         ++p;
 107                 }
 108         }
 109
 110         /* Main loop: Scan digits, find decimal point, if present.
 111          * We don't allow exponentials, so no scientific notation
 112          * (but note that E for Exa might look like e to some!).
 113          * Advance 'p' to end, to get scale factor.
 114          */
 115         for (; isascii((unsigned char)*p) && (isdigit((unsigned char)*p) || *p=='.'); ++p) {
 116                 if (*p == '.') {
 117                         if (fract_digits > 0) { /* oops, more than one '.' */
 118                                 errno = EINVAL;
 119                                 return -1;
 120                         }
 121                         fract_digits = 1;
 122                         continue;
 123                 }
 124
 125                 i = (*p) - '0';                 /* whew! finally a digit we can use */
 126                 if (fract_digits > 0) {
 127                         if (fract_digits >= MAX_DIGITS-1)
 128                                 /* ignore extra fractional digits */
 129                                 continue;
 130                         fract_digits++;         /* for later scaling */
 131                         fpart *= 10;
 132                         fpart += i;
 133                 } else {                                /* normal digit */
 134                         if (++ndigits >= MAX_DIGITS) {
 135                                 errno = ERANGE;
 136                                 return -1;
 137                         }
 138                         whole *= 10;
 139                         whole += i;
 140                 }
 141         }
 142
 143         if (sign) {
 144                 whole *= sign;
 145                 fpart *= sign;
 146         }
 147
 148         /* If no scale factor given, we're done. fraction is discarded. */
 149         if (!*p) {
 150                 *result = whole;
 151                 return 0;
 152         }
 153
 154         /* Validate scale factor, and scale whole and fraction by it. */
 155         for (i = 0; i < SCALE_LENGTH; i++) {
 156
 157                 /** Are we there yet? */
 158                 if (*p == scale_chars[i] ||
 159                         *p == tolower((unsigned char)scale_chars[i])) {
 160
 161                         /* If it ends with alphanumerics after the scale char, bad. */
 162                         if (isalnum((unsigned char)*(p+1))) {
 163                                 errno = EINVAL;
 164                                 return -1;
 165                         }
 166                         scale_fact = scale_factors[i];
 167
 168                         /* scale whole part */
 169                         whole *= scale_fact;
 170
 171                         /* truncate fpart so it does't overflow.
 172                          * then scale fractional part.
 173                          */
 174                         while (fpart >= LLONG_MAX / scale_fact) {
 175                                 fpart /= 10;
 176                                 fract_digits--;
 177                         }
 178                         fpart *= scale_fact;
 179                         if (fract_digits > 0) {
 180                                 for (i = 0; i < fract_digits -1; i++)
 181                                         fpart /= 10;
 182                         }
 183                         whole += fpart;
 184                         *result = whole;
 185                         return 0;
 186                 }
 187         }
 188         errno = ERANGE;
 189         return -1;
 190 }
 191 #endif
 192
 193 /* Format the given "number" into human-readable form in "result".
 194  * Result must point to an allocated buffer of length FMT_SCALED_STRSIZE.
 195  * Return 0 on success, -1 and errno set if error.
 196  */
 197 int
 198 fmt_scaled(long long number, char *result)
 199 {
 200         long long abval, fract = 0;
 201         unsigned int i;
 202         unit_type unit = NONE;
 203
 204         abval = (number < 0LL) ? -number : number;      /* no long long_abs yet */
 205
 206         /* Not every negative long long has a positive representation.
 207          * Also check for numbers that are just too darned big to format
 208          */
 209         if (abval < 0 || abval / 1024 >= scale_factors[SCALE_LENGTH-1]) {
 210                 errno = ERANGE;
 211                 return -1;
 212         }
 213
 214         /* scale whole part; get unscaled fraction */
 215         for (i = 0; i < SCALE_LENGTH; i++) {
 216                 if (abval/1024 < scale_factors[i]) {
 217                         unit = units[i];
 218                         fract = (i == 0) ? 0 : abval % scale_factors[i];
 219                         number /= scale_factors[i];
 220                         if (i > 0)
 221                                 fract /= scale_factors[i - 1];
 222                         break;
 223                 }
 224         }
 225
 226         fract = (10 * fract + 512) / 1024;
 227         /* if the result would be >= 10, round main number */
 228         if (fract == 10) {
 229                 if (number >= 0)
 230                         number++;
 231                 else
 232                         number--;
 233                 fract = 0;
 234         }
 235
 236         if (number == 0)
 237                 strlcpy(result, "0B", FMT_SCALED_STRSIZE);
 238         else if (unit == NONE || number >= 100 || number <= -100) {
 239                 if (fract >= 5) {
 240                         if (number >= 0)
 241                                 number++;
 242                         else
 243                                 number--;
 244                 }
 245                 (void)snprintf(result, FMT_SCALED_STRSIZE, "%lld%c",
 246                         number, scale_chars[unit]);
 247         } else
 248                 (void)snprintf(result, FMT_SCALED_STRSIZE, "%lld.%1lld%c",
 249                         number, fract, scale_chars[unit]);
 250
 251         return 0;
 252 }
 253
 254 #ifdef  MAIN
 255 /*
 256  * This is the original version of the program in the man page.
 257  * Copy-and-paste whatever you need from it.
 258  */
 259 int
 260 main(int argc, char **argv)
 261 {
 262         char *cinput = "1.5K", buf[FMT_SCALED_STRSIZE];
 263         long long ninput = 10483892, result;
 264
 265         if (scan_scaled(cinput, &result) == 0)
 266                 printf("\"%s\" -> %lld\n", cinput, result);
 267         else
 268                 perror(cinput);
 269
 270         if (fmt_scaled(ninput, buf) == 0)
 271                 printf("%lld -> \"%s\"\n", ninput, buf);
 272         else
 273                 fprintf(stderr, "%lld invalid (%s)\n", ninput, strerror(errno));
 274
 275         return 0;
 276 }
 277 #endif
 278
 279 #endif /* HAVE_FMT_SCALED */