strtoll.c (4486B)
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 #include <limits.h> 35 #include <errno.h> 36 #include <ctype.h> 37 #include <stdlib.h> 38 39 /* 40 * Convert a string to a long long integer. 41 * 42 * Assumes that the upper and lower case 43 * alphabets and digits are each contiguous. 44 */ 45 long long 46 strtoll(const char * __restrict nptr, char ** __restrict endptr, int base) 47 { 48 const char *s; 49 unsigned long long acc; 50 char c; 51 unsigned long long cutoff; 52 int neg, any, cutlim; 53 54 /* 55 * Skip white space and pick up leading +/- sign if any. 56 * If base is 0, allow 0x for hex and 0 for octal, else 57 * assume decimal; if base is already 16, allow 0x. 58 */ 59 s = nptr; 60 do { 61 c = *s++; 62 } while (isspace((unsigned char)c)); 63 if (c == '-') { 64 neg = 1; 65 c = *s++; 66 } else { 67 neg = 0; 68 if (c == '+') 69 c = *s++; 70 } 71 if ((base == 0 || base == 16) && 72 c == '0' && (*s == 'x' || *s == 'X') && 73 ((s[1] >= '0' && s[1] <= '9') || 74 (s[1] >= 'A' && s[1] <= 'F') || 75 (s[1] >= 'a' && s[1] <= 'f'))) { 76 c = s[1]; 77 s += 2; 78 base = 16; 79 } 80 if (base == 0) 81 base = c == '0' ? 8 : 10; 82 acc = any = 0; 83 if (base < 2 || base > 36) 84 goto noconv; 85 86 /* 87 * Compute the cutoff value between legal numbers and illegal 88 * numbers. That is the largest legal value, divided by the 89 * base. An input number that is greater than this value, if 90 * followed by a legal input character, is too big. One that 91 * is equal to this value may be valid or not; the limit 92 * between valid and invalid numbers is then based on the last 93 * digit. For instance, if the range for quads is 94 * [-9223372036854775808..9223372036854775807] and the input base 95 * is 10, cutoff will be set to 922337203685477580 and cutlim to 96 * either 7 (neg==0) or 8 (neg==1), meaning that if we have 97 * accumulated a value > 922337203685477580, or equal but the 98 * next digit is > 7 (or 8), the number is too big, and we will 99 * return a range error. 100 * 101 * Set 'any' if any `digits' consumed; make it negative to indicate 102 * overflow. 103 */ 104 cutoff = neg ? (unsigned long long)-(LLONG_MIN + LLONG_MAX) + LLONG_MAX 105 : LLONG_MAX; 106 cutlim = cutoff % base; 107 cutoff /= base; 108 for ( ; ; c = *s++) { 109 if (c >= '0' && c <= '9') 110 c -= '0'; 111 else if (c >= 'A' && c <= 'Z') 112 c -= 'A' - 10; 113 else if (c >= 'a' && c <= 'z') 114 c -= 'a' - 10; 115 else 116 break; 117 if (c >= base) 118 break; 119 if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim)) 120 any = -1; 121 else { 122 any = 1; 123 acc *= base; 124 acc += c; 125 } 126 } 127 if (any < 0) { 128 acc = neg ? LLONG_MIN : LLONG_MAX; 129 errno = ERANGE; 130 } else if (!any) { 131 noconv: 132 errno = EINVAL; 133 } else if (neg) 134 acc = -acc; 135 if (endptr != NULL) 136 *endptr = (char *)(any ? s - 1 : nptr); 137 return (acc); 138 }