expand_number.c revision 254600
1/*- 2 * Copyright (c) 2007 Eric Anderson <anderson@FreeBSD.org> 3 * Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org> 4 * 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 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28#include <sys/cdefs.h> 29__FBSDID("$FreeBSD: head/lib/libutil/expand_number.c 254600 2013-08-21 16:46:06Z pluknet $"); 30 31#include <sys/types.h> 32#include <ctype.h> 33#include <errno.h> 34#include <inttypes.h> 35#include <libutil.h> 36#include <stdint.h> 37 38/* 39 * Convert an expression of the following forms to a uint64_t. 40 * 1) A positive decimal number. 41 * 2) A positive decimal number followed by a 'b' or 'B' (mult by 1). 42 * 3) A positive decimal number followed by a 'k' or 'K' (mult by 1 << 10). 43 * 4) A positive decimal number followed by a 'm' or 'M' (mult by 1 << 20). 44 * 5) A positive decimal number followed by a 'g' or 'G' (mult by 1 << 30). 45 * 6) A positive decimal number followed by a 't' or 'T' (mult by 1 << 40). 46 * 7) A positive decimal number followed by a 'p' or 'P' (mult by 1 << 50). 47 * 8) A positive decimal number followed by a 'e' or 'E' (mult by 1 << 60). 48 */ 49int 50expand_number(const char *buf, uint64_t *num) 51{ 52 uint64_t number; 53 unsigned shift; 54 char *endptr; 55 56 number = strtoumax(buf, &endptr, 0); 57 58 if (number == UINTMAX_MAX && errno == ERANGE) { 59 return (-1); 60 } 61 62 if (endptr == buf) { 63 /* No valid digits. */ 64 errno = EINVAL; 65 return (-1); 66 } 67 68 switch (tolower((unsigned char)*endptr)) { 69 case 'e': 70 shift = 60; 71 break; 72 case 'p': 73 shift = 50; 74 break; 75 case 't': 76 shift = 40; 77 break; 78 case 'g': 79 shift = 30; 80 break; 81 case 'm': 82 shift = 20; 83 break; 84 case 'k': 85 shift = 10; 86 break; 87 case 'b': 88 case '\0': /* No unit. */ 89 *num = number; 90 return (0); 91 default: 92 /* Unrecognized unit. */ 93 errno = EINVAL; 94 return (-1); 95 } 96 97 if ((number << shift) >> shift != number) { 98 /* Overflow */ 99 errno = ERANGE; 100 return (-1); 101 } 102 103 *num = number << shift; 104 return (0); 105} 106