1 /*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * 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. [rescinded 22 July 1999] 14 * 4. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 /* 32 33 @deftypefn Supplemental {long int} strtol (const char *@var{string}, @ 34 char **@var{endptr}, int @var{base}) 35 @deftypefnx Supplemental {unsigned long int} strtoul (const char *@var{string}, @ 36 char **@var{endptr}, int @var{base}) 37 38 The @code{strtol} function converts the string in @var{string} to a 39 long integer value according to the given @var{base}, which must be 40 between 2 and 36 inclusive, or be the special value 0. If @var{base} 41 is 0, @code{strtol} will look for the prefixes @code{0} and @code{0x} 42 to indicate bases 8 and 16, respectively, else default to base 10. 43 When the base is 16 (either explicitly or implicitly), a prefix of 44 @code{0x} is allowed. The handling of @var{endptr} is as that of 45 @code{strtod} above. The @code{strtoul} function is the same, except 46 that the converted value is unsigned. 47 48 @end deftypefn 49 50 */ 51 52 #ifdef HAVE_CONFIG_H 53 #include "config.h" 54 #endif 55 #ifdef HAVE_LIMITS_H 56 #include <limits.h> 57 #endif 58 #ifdef HAVE_SYS_PARAM_H 59 #include <sys/param.h> 60 #endif 61 #include <errno.h> 62 #ifdef NEED_DECLARATION_ERRNO 63 extern int errno; 64 #endif 65 #include "safe-ctype.h" 66 67 /* FIXME: It'd be nice to configure around these, but the include files are too 68 painful. These macros should at least be more portable than hardwired hex 69 constants. */ 70 71 #ifndef ULONG_MAX 72 #define ULONG_MAX ((unsigned long)(~0L)) /* 0xFFFFFFFF */ 73 #endif 74 75 #ifndef LONG_MAX 76 #define LONG_MAX ((long)(ULONG_MAX >> 1)) /* 0x7FFFFFFF */ 77 #endif 78 79 #ifndef LONG_MIN 80 #define LONG_MIN ((long)(~LONG_MAX)) /* 0x80000000 */ 81 #endif 82 83 /* 84 * Convert a string to a long integer. 85 * 86 * Ignores `locale' stuff. Assumes that the upper and lower case 87 * alphabets and digits are each contiguous. 88 */ 89 long 90 strtol(const char *nptr, char **endptr, register int base) 91 { 92 register const char *s = nptr; 93 register unsigned long acc; 94 register int c; 95 register unsigned long cutoff; 96 register int neg = 0, any, cutlim; 97 98 /* 99 * Skip white space and pick up leading +/- sign if any. 100 * If base is 0, allow 0x for hex and 0 for octal, else 101 * assume decimal; if base is already 16, allow 0x. 102 */ 103 do { 104 c = *s++; 105 } while (ISSPACE(c)); 106 if (c == '-') { 107 neg = 1; 108 c = *s++; 109 } else if (c == '+') 110 c = *s++; 111 if ((base == 0 || base == 16) && 112 c == '0' && (*s == 'x' || *s == 'X')) { 113 c = s[1]; 114 s += 2; 115 base = 16; 116 } 117 if (base == 0) 118 base = c == '0' ? 8 : 10; 119 120 /* 121 * Compute the cutoff value between legal numbers and illegal 122 * numbers. That is the largest legal value, divided by the 123 * base. An input number that is greater than this value, if 124 * followed by a legal input character, is too big. One that 125 * is equal to this value may be valid or not; the limit 126 * between valid and invalid numbers is then based on the last 127 * digit. For instance, if the range for longs is 128 * [-2147483648..2147483647] and the input base is 10, 129 * cutoff will be set to 214748364 and cutlim to either 130 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated 131 * a value > 214748364, or equal but the next digit is > 7 (or 8), 132 * the number is too big, and we will return a range error. 133 * 134 * Set any if any `digits' consumed; make it negative to indicate 135 * overflow. 136 */ 137 cutoff = neg ? -(unsigned long)LONG_MIN : LONG_MAX; 138 cutlim = cutoff % (unsigned long)base; 139 cutoff /= (unsigned long)base; 140 for (acc = 0, any = 0;; c = *s++) { 141 if (ISDIGIT(c)) 142 c -= '0'; 143 else if (ISALPHA(c)) 144 c -= ISUPPER(c) ? 'A' - 10 : 'a' - 10; 145 else 146 break; 147 if (c >= base) 148 break; 149 if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim)) 150 any = -1; 151 else { 152 any = 1; 153 acc *= base; 154 acc += c; 155 } 156 } 157 if (any < 0) { 158 acc = neg ? LONG_MIN : LONG_MAX; 159 errno = ERANGE; 160 } else if (neg) 161 acc = -acc; 162 if (endptr != 0) 163 *endptr = (char *) (any ? s - 1 : nptr); 164 return (acc); 165 } 166
