Greg Hartman | bd77cf7 | 2015-02-25 13:21:06 -0800 | [diff] [blame] | 1 | /* $OpenBSD: fmt_scaled.c,v 1.9 2007/03/20 03:42:52 tedu Exp $ */ |
| 2 | |
| 3 | /* |
| 4 | * Copyright (c) 2001, 2002, 2003 Ian F. Darwin. All rights reserved. |
| 5 | * |
| 6 | * Redistribution and use in source and binary forms, with or without |
| 7 | * modification, are permitted provided that the following conditions |
| 8 | * are met: |
| 9 | * 1. Redistributions of source code must retain the above copyright |
| 10 | * notice, this list of conditions and the following disclaimer. |
| 11 | * 2. Redistributions in binary form must reproduce the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer in the |
| 13 | * documentation and/or other materials provided with the distribution. |
| 14 | * 3. The name of the author may not be used to endorse or promote products |
| 15 | * derived from this software without specific prior written permission. |
| 16 | * |
| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 27 | */ |
| 28 | |
| 29 | /* OPENBSD ORIGINAL: lib/libutil/fmt_scaled.c */ |
| 30 | |
| 31 | /* |
| 32 | * fmt_scaled: Format numbers scaled for human comprehension |
| 33 | * scan_scaled: Scan numbers in this format. |
| 34 | * |
| 35 | * "Human-readable" output uses 4 digits max, and puts a unit suffix at |
| 36 | * the end. Makes output compact and easy-to-read esp. on huge disks. |
| 37 | * Formatting code was originally in OpenBSD "df", converted to library routine. |
| 38 | * Scanning code written for OpenBSD libutil. |
| 39 | */ |
| 40 | |
| 41 | #include "includes.h" |
| 42 | |
| 43 | #ifndef HAVE_FMT_SCALED |
| 44 | |
| 45 | #include <stdio.h> |
| 46 | #include <stdlib.h> |
| 47 | #include <errno.h> |
| 48 | #include <string.h> |
| 49 | #include <ctype.h> |
| 50 | #include <limits.h> |
| 51 | |
| 52 | typedef enum { |
| 53 | NONE = 0, KILO = 1, MEGA = 2, GIGA = 3, TERA = 4, PETA = 5, EXA = 6 |
| 54 | } unit_type; |
| 55 | |
| 56 | /* These three arrays MUST be in sync! XXX make a struct */ |
| 57 | static unit_type units[] = { NONE, KILO, MEGA, GIGA, TERA, PETA, EXA }; |
| 58 | static char scale_chars[] = "BKMGTPE"; |
| 59 | static long long scale_factors[] = { |
| 60 | 1LL, |
| 61 | 1024LL, |
| 62 | 1024LL*1024, |
| 63 | 1024LL*1024*1024, |
| 64 | 1024LL*1024*1024*1024, |
| 65 | 1024LL*1024*1024*1024*1024, |
| 66 | 1024LL*1024*1024*1024*1024*1024, |
| 67 | }; |
| 68 | #define SCALE_LENGTH (sizeof(units)/sizeof(units[0])) |
| 69 | |
| 70 | #define MAX_DIGITS (SCALE_LENGTH * 3) /* XXX strlen(sprintf("%lld", -1)? */ |
| 71 | |
| 72 | /** Convert the given input string "scaled" into numeric in "result". |
| 73 | * Return 0 on success, -1 and errno set on error. |
| 74 | */ |
| 75 | int |
| 76 | scan_scaled(char *scaled, long long *result) |
| 77 | { |
| 78 | char *p = scaled; |
| 79 | int sign = 0; |
| 80 | unsigned int i, ndigits = 0, fract_digits = 0; |
| 81 | long long scale_fact = 1, whole = 0, fpart = 0; |
| 82 | |
| 83 | /* Skip leading whitespace */ |
| 84 | while (isascii(*p) && isspace(*p)) |
| 85 | ++p; |
| 86 | |
| 87 | /* Then at most one leading + or - */ |
| 88 | while (*p == '-' || *p == '+') { |
| 89 | if (*p == '-') { |
| 90 | if (sign) { |
| 91 | errno = EINVAL; |
| 92 | return -1; |
| 93 | } |
| 94 | sign = -1; |
| 95 | ++p; |
| 96 | } else if (*p == '+') { |
| 97 | if (sign) { |
| 98 | errno = EINVAL; |
| 99 | return -1; |
| 100 | } |
| 101 | sign = +1; |
| 102 | ++p; |
| 103 | } |
| 104 | } |
| 105 | |
| 106 | /* Main loop: Scan digits, find decimal point, if present. |
| 107 | * We don't allow exponentials, so no scientific notation |
| 108 | * (but note that E for Exa might look like e to some!). |
| 109 | * Advance 'p' to end, to get scale factor. |
| 110 | */ |
| 111 | for (; isascii(*p) && (isdigit(*p) || *p=='.'); ++p) { |
| 112 | if (*p == '.') { |
| 113 | if (fract_digits > 0) { /* oops, more than one '.' */ |
| 114 | errno = EINVAL; |
| 115 | return -1; |
| 116 | } |
| 117 | fract_digits = 1; |
| 118 | continue; |
| 119 | } |
| 120 | |
| 121 | i = (*p) - '0'; /* whew! finally a digit we can use */ |
| 122 | if (fract_digits > 0) { |
| 123 | if (fract_digits >= MAX_DIGITS-1) |
| 124 | /* ignore extra fractional digits */ |
| 125 | continue; |
| 126 | fract_digits++; /* for later scaling */ |
| 127 | fpart *= 10; |
| 128 | fpart += i; |
| 129 | } else { /* normal digit */ |
| 130 | if (++ndigits >= MAX_DIGITS) { |
| 131 | errno = ERANGE; |
| 132 | return -1; |
| 133 | } |
| 134 | whole *= 10; |
| 135 | whole += i; |
| 136 | } |
| 137 | } |
| 138 | |
| 139 | if (sign) { |
| 140 | whole *= sign; |
| 141 | fpart *= sign; |
| 142 | } |
| 143 | |
| 144 | /* If no scale factor given, we're done. fraction is discarded. */ |
| 145 | if (!*p) { |
| 146 | *result = whole; |
| 147 | return 0; |
| 148 | } |
| 149 | |
| 150 | /* Validate scale factor, and scale whole and fraction by it. */ |
| 151 | for (i = 0; i < SCALE_LENGTH; i++) { |
| 152 | |
| 153 | /** Are we there yet? */ |
| 154 | if (*p == scale_chars[i] || |
| 155 | *p == tolower(scale_chars[i])) { |
| 156 | |
| 157 | /* If it ends with alphanumerics after the scale char, bad. */ |
| 158 | if (isalnum(*(p+1))) { |
| 159 | errno = EINVAL; |
| 160 | return -1; |
| 161 | } |
| 162 | scale_fact = scale_factors[i]; |
| 163 | |
| 164 | /* scale whole part */ |
| 165 | whole *= scale_fact; |
| 166 | |
| 167 | /* truncate fpart so it does't overflow. |
| 168 | * then scale fractional part. |
| 169 | */ |
| 170 | while (fpart >= LLONG_MAX / scale_fact) { |
| 171 | fpart /= 10; |
| 172 | fract_digits--; |
| 173 | } |
| 174 | fpart *= scale_fact; |
| 175 | if (fract_digits > 0) { |
| 176 | for (i = 0; i < fract_digits -1; i++) |
| 177 | fpart /= 10; |
| 178 | } |
| 179 | whole += fpart; |
| 180 | *result = whole; |
| 181 | return 0; |
| 182 | } |
| 183 | } |
| 184 | errno = ERANGE; |
| 185 | return -1; |
| 186 | } |
| 187 | |
| 188 | /* Format the given "number" into human-readable form in "result". |
| 189 | * Result must point to an allocated buffer of length FMT_SCALED_STRSIZE. |
| 190 | * Return 0 on success, -1 and errno set if error. |
| 191 | */ |
| 192 | int |
| 193 | fmt_scaled(long long number, char *result) |
| 194 | { |
| 195 | long long abval, fract = 0; |
| 196 | unsigned int i; |
| 197 | unit_type unit = NONE; |
| 198 | |
| 199 | abval = (number < 0LL) ? -number : number; /* no long long_abs yet */ |
| 200 | |
| 201 | /* Not every negative long long has a positive representation. |
| 202 | * Also check for numbers that are just too darned big to format |
| 203 | */ |
| 204 | if (abval < 0 || abval / 1024 >= scale_factors[SCALE_LENGTH-1]) { |
| 205 | errno = ERANGE; |
| 206 | return -1; |
| 207 | } |
| 208 | |
| 209 | /* scale whole part; get unscaled fraction */ |
| 210 | for (i = 0; i < SCALE_LENGTH; i++) { |
| 211 | if (abval/1024 < scale_factors[i]) { |
| 212 | unit = units[i]; |
| 213 | fract = (i == 0) ? 0 : abval % scale_factors[i]; |
| 214 | number /= scale_factors[i]; |
| 215 | if (i > 0) |
| 216 | fract /= scale_factors[i - 1]; |
| 217 | break; |
| 218 | } |
| 219 | } |
| 220 | |
| 221 | fract = (10 * fract + 512) / 1024; |
| 222 | /* if the result would be >= 10, round main number */ |
| 223 | if (fract == 10) { |
| 224 | if (number >= 0) |
| 225 | number++; |
| 226 | else |
| 227 | number--; |
| 228 | fract = 0; |
| 229 | } |
| 230 | |
| 231 | if (number == 0) |
| 232 | strlcpy(result, "0B", FMT_SCALED_STRSIZE); |
| 233 | else if (unit == NONE || number >= 100 || number <= -100) { |
| 234 | if (fract >= 5) { |
| 235 | if (number >= 0) |
| 236 | number++; |
| 237 | else |
| 238 | number--; |
| 239 | } |
| 240 | (void)snprintf(result, FMT_SCALED_STRSIZE, "%lld%c", |
| 241 | number, scale_chars[unit]); |
| 242 | } else |
| 243 | (void)snprintf(result, FMT_SCALED_STRSIZE, "%lld.%1lld%c", |
| 244 | number, fract, scale_chars[unit]); |
| 245 | |
| 246 | return 0; |
| 247 | } |
| 248 | |
| 249 | #ifdef MAIN |
| 250 | /* |
| 251 | * This is the original version of the program in the man page. |
| 252 | * Copy-and-paste whatever you need from it. |
| 253 | */ |
| 254 | int |
| 255 | main(int argc, char **argv) |
| 256 | { |
| 257 | char *cinput = "1.5K", buf[FMT_SCALED_STRSIZE]; |
| 258 | long long ninput = 10483892, result; |
| 259 | |
| 260 | if (scan_scaled(cinput, &result) == 0) |
| 261 | printf("\"%s\" -> %lld\n", cinput, result); |
| 262 | else |
| 263 | perror(cinput); |
| 264 | |
| 265 | if (fmt_scaled(ninput, buf) == 0) |
| 266 | printf("%lld -> \"%s\"\n", ninput, buf); |
| 267 | else |
| 268 | fprintf(stderr, "%lld invalid (%s)\n", ninput, strerror(errno)); |
| 269 | |
| 270 | return 0; |
| 271 | } |
| 272 | #endif |
| 273 | |
| 274 | #endif /* HAVE_FMT_SCALED */ |