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b3ef88dc | 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 */ |