1 /* $NetBSD: fmt_scaled.c,v 1.1 2009/06/07 22:38:46 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 2009/06/07 22:38:46 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 */ 280