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 [rescinded 22 July 1999] 14 * 4.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}, char **@var{endptr}, int @var{base}) 34 @deftypefnx Supplemental {unsigned long int} strtoul (const char *@var{string}, char **@var{endptr}, int @var{base}) 35 36 The @code{strtol} function converts the string in @var{string} to a 37 long integer value according to the given @var{base}, which must be 38 between 2 and 36 inclusive, or be the special value 0. If @var{base} 39 is 0, @code{strtol} will look for the prefixes @code{0} and @code{0x} 40 to indicate bases 8 and 16, respectively, else default to base 10. 41 When the base is 16 (either explicitly or implicitly), a prefix of 42 @code{0x} is allowed. The handling of @var{endptr} is as that of 43 @code{strtod} above. The @code{strtoul} function is the same, except 44 that the converted value is unsigned. 45 46 @end deftypefn 47 48 */ 49 50 #ifdef HAVE_CONFIG_H 51 #include "config.h" 52 #endif 53 #ifdef HAVE_LIMITS_H 54 #include <limits.h> 55 #endif 56 #ifdef HAVE_SYS_PARAM_H 57 #include <sys/param.h> 58 #endif 59 #include <errno.h> 60 #ifdef NEED_DECLARATION_ERRNO 61 extern int errno; 62 #endif 63 #include "safe-ctype.h" 64 65 /* FIXME: It'd be nice to configure around these, but the include files are too 66 painful. These macros should at least be more portable than hardwired hex 67 constants. */ 68 69 #ifndef ULONG_MAX 70 #define ULONG_MAX ((unsigned long)(~0L)) /* 0xFFFFFFFF */ 71 #endif 72 73 #ifndef LONG_MAX 74 #define LONG_MAX ((long)(ULONG_MAX >> 1)) /* 0x7FFFFFFF */ 75 #endif 76 77 #ifndef LONG_MIN 78 #define LONG_MIN ((long)(~LONG_MAX)) /* 0x80000000 */ 79 #endif 80 81 /* 82 * Convert a string to a long integer. 83 * 84 * Ignores `locale' stuff. Assumes that the upper and lower case 85 * alphabets and digits are each contiguous. 86 */ 87 long 88 strtol(const char *nptr, char **endptr, register int base) 89 { 90 register const char *s = nptr; 91 register unsigned long acc; 92 register int c; 93 register unsigned long cutoff; 94 register int neg = 0, any, cutlim; 95 96 /* 97 * Skip white space and pick up leading +/- sign if any. 98 * If base is 0, allow 0x for hex and 0 for octal, else 99 * assume decimal; if base is already 16, allow 0x. 100 */ 101 do { 102 c = *s++; 103 } while (ISSPACE(c)); 104 if (c == '-') { 105 neg = 1; 106 c = *s++; 107 } else if (c == '+') 108 c = *s++; 109 if ((base == 0 || base == 16) && 110 c == '0' && (*s == 'x' || *s == 'X')) { 111 c = s[1]; 112 s += 2; 113 base = 16; 114 } 115 if (base == 0) 116 base = c == '0' ? 8 : 10; 117 118 /* 119 * Compute the cutoff value between legal numbers and illegal 120 * numbers. That is the largest legal value, divided by the 121 * base. An input number that is greater than this value, if 122 * followed by a legal input character, is too big. One that 123 * is equal to this value may be valid or not; the limit 124 * between valid and invalid numbers is then based on the last 125 * digit. For instance, if the range for longs is 126 * [-2147483648..2147483647] and the input base is 10, 127 * cutoff will be set to 214748364 and cutlim to either 128 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated 129 * a value > 214748364, or equal but the next digit is > 7 (or 8), 130 * the number is too big, and we will return a range error. 131 * 132 * Set any if any `digits' consumed; make it negative to indicate 133 * overflow. 134 */ 135 cutoff = neg ? -(unsigned long)LONG_MIN : LONG_MAX; 136 cutlim = cutoff % (unsigned long)base; 137 cutoff /= (unsigned long)base; 138 for (acc = 0, any = 0;; c = *s++) { 139 if (ISDIGIT(c)) 140 c -= '0'; 141 else if (ISALPHA(c)) 142 c -= ISUPPER(c) ? 'A' - 10 : 'a' - 10; 143 else 144 break; 145 if (c >= base) 146 break; 147 if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim)) 148 any = -1; 149 else { 150 any = 1; 151 acc *= base; 152 acc += c; 153 } 154 } 155 if (any < 0) { 156 acc = neg ? LONG_MIN : LONG_MAX; 157 errno = ERANGE; 158 } else if (neg) 159 acc = -acc; 160 if (endptr != 0) 161 *endptr = (char *) (any ? s - 1 : nptr); 162 return (acc); 163 } 164