2 * Copyright (c) 1990 The Regents of the University of California.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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 [rescinded 22 July 1999]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.
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
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27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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})
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.
56 #ifdef HAVE_SYS_PARAM_H
57 #include <sys/param.h>
60 #ifdef NEED_DECLARATION_ERRNO
63 #include "safe-ctype.h"
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
70 #define ULONG_MAX ((unsigned long)(~0L)) /* 0xFFFFFFFF */
74 #define LONG_MAX ((long)(ULONG_MAX >> 1)) /* 0x7FFFFFFF */
78 #define LONG_MIN ((long)(~LONG_MAX)) /* 0x80000000 */
82 * Convert a string to a long integer.
84 * Ignores `locale' stuff. Assumes that the upper and lower case
85 * alphabets and digits are each contiguous.
88 strtol(nptr
, endptr
, base
)
93 register const char *s
= nptr
;
94 register unsigned long acc
;
96 register unsigned long cutoff
;
97 register int neg
= 0, any
, cutlim
;
100 * Skip white space and pick up leading +/- sign if any.
101 * If base is 0, allow 0x for hex and 0 for octal, else
102 * assume decimal; if base is already 16, allow 0x.
106 } while (ISSPACE(c
));
112 if ((base
== 0 || base
== 16) &&
113 c
== '0' && (*s
== 'x' || *s
== 'X')) {
119 base
= c
== '0' ? 8 : 10;
122 * Compute the cutoff value between legal numbers and illegal
123 * numbers. That is the largest legal value, divided by the
124 * base. An input number that is greater than this value, if
125 * followed by a legal input character, is too big. One that
126 * is equal to this value may be valid or not; the limit
127 * between valid and invalid numbers is then based on the last
128 * digit. For instance, if the range for longs is
129 * [-2147483648..2147483647] and the input base is 10,
130 * cutoff will be set to 214748364 and cutlim to either
131 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
132 * a value > 214748364, or equal but the next digit is > 7 (or 8),
133 * the number is too big, and we will return a range error.
135 * Set any if any `digits' consumed; make it negative to indicate
138 cutoff
= neg
? -(unsigned long)LONG_MIN
: LONG_MAX
;
139 cutlim
= cutoff
% (unsigned long)base
;
140 cutoff
/= (unsigned long)base
;
141 for (acc
= 0, any
= 0;; c
= *s
++) {
145 c
-= ISUPPER(c
) ? 'A' - 10 : 'a' - 10;
150 if (any
< 0 || acc
> cutoff
|| acc
== cutoff
&& c
> cutlim
)
159 acc
= neg
? LONG_MIN
: LONG_MAX
;
164 *endptr
= (char *) (any
? s
- 1 : nptr
);
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