| /* $OpenBSD: fmt_scaled.c,v 1.16 2017/03/16 02:40:46 dtucker Exp $ */ |
| |
| /* |
| * Copyright (c) 2001, 2002, 2003 Ian F. Darwin. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| /* OPENBSD ORIGINAL: lib/libutil/fmt_scaled.c */ |
| |
| /* |
| * fmt_scaled: Format numbers scaled for human comprehension |
| * scan_scaled: Scan numbers in this format. |
| * |
| * "Human-readable" output uses 4 digits max, and puts a unit suffix at |
| * the end. Makes output compact and easy-to-read esp. on huge disks. |
| * Formatting code was originally in OpenBSD "df", converted to library routine. |
| * Scanning code written for OpenBSD libutil. |
| */ |
| |
| #include "includes.h" |
| |
| #ifndef HAVE_FMT_SCALED |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <errno.h> |
| #include <string.h> |
| #include <ctype.h> |
| #include <limits.h> |
| |
| typedef enum { |
| NONE = 0, KILO = 1, MEGA = 2, GIGA = 3, TERA = 4, PETA = 5, EXA = 6 |
| } unit_type; |
| |
| /* These three arrays MUST be in sync! XXX make a struct */ |
| static unit_type units[] = { NONE, KILO, MEGA, GIGA, TERA, PETA, EXA }; |
| static char scale_chars[] = "BKMGTPE"; |
| static long long scale_factors[] = { |
| 1LL, |
| 1024LL, |
| 1024LL*1024, |
| 1024LL*1024*1024, |
| 1024LL*1024*1024*1024, |
| 1024LL*1024*1024*1024*1024, |
| 1024LL*1024*1024*1024*1024*1024, |
| }; |
| #define SCALE_LENGTH (sizeof(units)/sizeof(units[0])) |
| |
| #define MAX_DIGITS (SCALE_LENGTH * 3) /* XXX strlen(sprintf("%lld", -1)? */ |
| |
| /* Convert the given input string "scaled" into numeric in "result". |
| * Return 0 on success, -1 and errno set on error. |
| */ |
| int |
| scan_scaled(char *scaled, long long *result) |
| { |
| char *p = scaled; |
| int sign = 0; |
| unsigned int i, ndigits = 0, fract_digits = 0; |
| long long scale_fact = 1, whole = 0, fpart = 0; |
| |
| /* Skip leading whitespace */ |
| while (isascii((unsigned char)*p) && isspace((unsigned char)*p)) |
| ++p; |
| |
| /* Then at most one leading + or - */ |
| while (*p == '-' || *p == '+') { |
| if (*p == '-') { |
| if (sign) { |
| errno = EINVAL; |
| return -1; |
| } |
| sign = -1; |
| ++p; |
| } else if (*p == '+') { |
| if (sign) { |
| errno = EINVAL; |
| return -1; |
| } |
| sign = +1; |
| ++p; |
| } |
| } |
| |
| /* Main loop: Scan digits, find decimal point, if present. |
| * We don't allow exponentials, so no scientific notation |
| * (but note that E for Exa might look like e to some!). |
| * Advance 'p' to end, to get scale factor. |
| */ |
| for (; isascii((unsigned char)*p) && |
| (isdigit((unsigned char)*p) || *p=='.'); ++p) { |
| if (*p == '.') { |
| if (fract_digits > 0) { /* oops, more than one '.' */ |
| errno = EINVAL; |
| return -1; |
| } |
| fract_digits = 1; |
| continue; |
| } |
| |
| i = (*p) - '0'; /* whew! finally a digit we can use */ |
| if (fract_digits > 0) { |
| if (fract_digits >= MAX_DIGITS-1) |
| /* ignore extra fractional digits */ |
| continue; |
| fract_digits++; /* for later scaling */ |
| if (fpart > LLONG_MAX / 10) { |
| errno = ERANGE; |
| return -1; |
| } |
| fpart *= 10; |
| if (i > LLONG_MAX - fpart) { |
| errno = ERANGE; |
| return -1; |
| } |
| fpart += i; |
| } else { /* normal digit */ |
| if (++ndigits >= MAX_DIGITS) { |
| errno = ERANGE; |
| return -1; |
| } |
| if (whole > LLONG_MAX / 10) { |
| errno = ERANGE; |
| return -1; |
| } |
| whole *= 10; |
| if (i > LLONG_MAX - whole) { |
| errno = ERANGE; |
| return -1; |
| } |
| whole += i; |
| } |
| } |
| |
| if (sign) { |
| whole *= sign; |
| fpart *= sign; |
| } |
| |
| /* If no scale factor given, we're done. fraction is discarded. */ |
| if (!*p) { |
| *result = whole; |
| return 0; |
| } |
| |
| /* Validate scale factor, and scale whole and fraction by it. */ |
| for (i = 0; i < SCALE_LENGTH; i++) { |
| |
| /* Are we there yet? */ |
| if (*p == scale_chars[i] || |
| *p == tolower((unsigned char)scale_chars[i])) { |
| |
| /* If it ends with alphanumerics after the scale char, bad. */ |
| if (isalnum((unsigned char)*(p+1))) { |
| errno = EINVAL; |
| return -1; |
| } |
| scale_fact = scale_factors[i]; |
| |
| /* check for overflow and underflow after scaling */ |
| if (whole > LLONG_MAX / scale_fact || |
| whole < LLONG_MIN / scale_fact) { |
| errno = ERANGE; |
| return -1; |
| } |
| |
| /* scale whole part */ |
| whole *= scale_fact; |
| |
| /* truncate fpart so it does't overflow. |
| * then scale fractional part. |
| */ |
| while (fpart >= LLONG_MAX / scale_fact) { |
| fpart /= 10; |
| fract_digits--; |
| } |
| fpart *= scale_fact; |
| if (fract_digits > 0) { |
| for (i = 0; i < fract_digits -1; i++) |
| fpart /= 10; |
| } |
| whole += fpart; |
| *result = whole; |
| return 0; |
| } |
| } |
| |
| /* Invalid unit or character */ |
| errno = EINVAL; |
| return -1; |
| } |
| |
| /* Format the given "number" into human-readable form in "result". |
| * Result must point to an allocated buffer of length FMT_SCALED_STRSIZE. |
| * Return 0 on success, -1 and errno set if error. |
| */ |
| int |
| fmt_scaled(long long number, char *result) |
| { |
| long long abval, fract = 0; |
| unsigned int i; |
| unit_type unit = NONE; |
| |
| abval = llabs(number); |
| |
| /* Not every negative long long has a positive representation. |
| * Also check for numbers that are just too darned big to format |
| */ |
| if (abval < 0 || abval / 1024 >= scale_factors[SCALE_LENGTH-1]) { |
| errno = ERANGE; |
| return -1; |
| } |
| |
| /* scale whole part; get unscaled fraction */ |
| for (i = 0; i < SCALE_LENGTH; i++) { |
| if (abval/1024 < scale_factors[i]) { |
| unit = units[i]; |
| fract = (i == 0) ? 0 : abval % scale_factors[i]; |
| number /= scale_factors[i]; |
| if (i > 0) |
| fract /= scale_factors[i - 1]; |
| break; |
| } |
| } |
| |
| fract = (10 * fract + 512) / 1024; |
| /* if the result would be >= 10, round main number */ |
| if (fract == 10) { |
| if (number >= 0) |
| number++; |
| else |
| number--; |
| fract = 0; |
| } |
| |
| if (number == 0) |
| strlcpy(result, "0B", FMT_SCALED_STRSIZE); |
| else if (unit == NONE || number >= 100 || number <= -100) { |
| if (fract >= 5) { |
| if (number >= 0) |
| number++; |
| else |
| number--; |
| } |
| (void)snprintf(result, FMT_SCALED_STRSIZE, "%lld%c", |
| number, scale_chars[unit]); |
| } else |
| (void)snprintf(result, FMT_SCALED_STRSIZE, "%lld.%1lld%c", |
| number, fract, scale_chars[unit]); |
| |
| return 0; |
| } |
| |
| #ifdef MAIN |
| /* |
| * This is the original version of the program in the man page. |
| * Copy-and-paste whatever you need from it. |
| */ |
| int |
| main(int argc, char **argv) |
| { |
| char *cinput = "1.5K", buf[FMT_SCALED_STRSIZE]; |
| long long ninput = 10483892, result; |
| |
| if (scan_scaled(cinput, &result) == 0) |
| printf("\"%s\" -> %lld\n", cinput, result); |
| else |
| perror(cinput); |
| |
| if (fmt_scaled(ninput, buf) == 0) |
| printf("%lld -> \"%s\"\n", ninput, buf); |
| else |
| fprintf(stderr, "%lld invalid (%s)\n", ninput, strerror(errno)); |
| |
| return 0; |
| } |
| #endif |
| |
| #endif /* HAVE_FMT_SCALED */ |