1 /*- 2 * Copyright (c) 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #if defined(LIBC_SCCS) && !defined(lint) 35 static char sccsid[] = "from @(#)strtol.c 8.1 (Berkeley) 6/4/93"; 36 #endif /* LIBC_SCCS and not lint */ 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include <ctype.h> 41 #include <errno.h> 42 #include <stdlib.h> 43 #include <inttypes.h> 44 45 /* 46 * Convert a string to an intmax_t integer. 47 * 48 * Assumes that the upper and lower case 49 * alphabets and digits are each contiguous. 50 */ 51 intmax_t 52 strtoimax(const char * __restrict nptr, char ** __restrict endptr, int base) 53 { 54 const char *s; 55 uintmax_t acc; 56 char c; 57 uintmax_t cutoff; 58 int neg, any, cutlim; 59 60 /* 61 * Skip white space and pick up leading +/- sign if any. 62 * If base is 0, allow 0x for hex and 0 for octal, else 63 * assume decimal; if base is already 16, allow 0x. 64 */ 65 s = nptr; 66 do { 67 c = *s++; 68 } while (isspace((unsigned char)c)); 69 if (c == '-') { 70 neg = 1; 71 c = *s++; 72 } else { 73 neg = 0; 74 if (c == '+') 75 c = *s++; 76 } 77 if ((base == 0 || base == 16) && 78 c == '0' && (*s == 'x' || *s == 'X') && 79 ((s[1] >= '0' && s[1] <= '9') || 80 (s[1] >= 'A' && s[1] <= 'F') || 81 (s[1] >= 'a' && s[1] <= 'f'))) { 82 c = s[1]; 83 s += 2; 84 base = 16; 85 } 86 if (base == 0) 87 base = c == '0' ? 8 : 10; 88 acc = any = 0; 89 if (base < 2 || base > 36) 90 goto noconv; 91 92 /* 93 * Compute the cutoff value between legal numbers and illegal 94 * numbers. That is the largest legal value, divided by the 95 * base. An input number that is greater than this value, if 96 * followed by a legal input character, is too big. One that 97 * is equal to this value may be valid or not; the limit 98 * between valid and invalid numbers is then based on the last 99 * digit. For instance, if the range for intmax_t is 100 * [-9223372036854775808..9223372036854775807] and the input base 101 * is 10, cutoff will be set to 922337203685477580 and cutlim to 102 * either 7 (neg==0) or 8 (neg==1), meaning that if we have 103 * accumulated a value > 922337203685477580, or equal but the 104 * next digit is > 7 (or 8), the number is too big, and we will 105 * return a range error. 106 * 107 * Set 'any' if any `digits' consumed; make it negative to indicate 108 * overflow. 109 */ 110 cutoff = neg ? (uintmax_t)-(INTMAX_MIN + INTMAX_MAX) + INTMAX_MAX 111 : INTMAX_MAX; 112 cutlim = cutoff % base; 113 cutoff /= base; 114 for ( ; ; c = *s++) { 115 if (c >= '0' && c <= '9') 116 c -= '0'; 117 else if (c >= 'A' && c <= 'Z') 118 c -= 'A' - 10; 119 else if (c >= 'a' && c <= 'z') 120 c -= 'a' - 10; 121 else 122 break; 123 if (c >= base) 124 break; 125 if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim)) 126 any = -1; 127 else { 128 any = 1; 129 acc *= base; 130 acc += c; 131 } 132 } 133 if (any < 0) { 134 acc = neg ? INTMAX_MIN : INTMAX_MAX; 135 errno = ERANGE; 136 } else if (!any) { 137 noconv: 138 errno = EINVAL; 139 } else if (neg) 140 acc = -acc; 141 if (endptr != NULL) 142 *endptr = (char *)(any ? s - 1 : nptr); 143 return (acc); 144 } 145