1 /* Copyright (c) 2002-2005 Michael Stumpf <mistumpf@de.pepperl-fuchs.com>
2 Copyright (c) 2006,2008 Dmitry Xmelkov
3
4 All rights reserved.
5
6 Redistribution and use in source and binary forms, with or without
7 modification, are permitted provided that the following conditions are met:
8
9 * Redistributions of source code must retain the above copyright
10 notice, this list of conditions and the following disclaimer.
11 * Redistributions in binary form must reproduce the above copyright
12 notice, this list of conditions and the following disclaimer in
13 the documentation and/or other materials provided with the
14 distribution.
15 * Neither the name of the copyright holders nor the names of
16 contributors may be used to endorse or promote products derived
17 from this software without specific prior written permission.
18
19 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
20 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
23 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 POSSIBILITY OF SUCH DAMAGE. */
30
31 /* $Id: strtof.c 2191 2010-11-05 13:45:57Z arcanum $ */
32
33 #include <ctype.h>
34 #include <errno.h>
35 #include <limits.h>
36 #include <math.h> /* INFINITY, NAN */
37 #include <stdlib.h>
38 #include <stdint.h>
39 #include <string.h>
40
41 /** The strtof() function converts the initial portion of the string pointed
42 to by \a nptr to float representation.
43
44 The expected form of the string is an optional plus ( \c '+' ) or minus
45 sign ( \c '-' ) followed by a sequence of digits optionally containing
46 a decimal-point character, optionally followed by an exponent. An
47 exponent consists of an \c 'E' or \c 'e', followed by an optional plus
48 or minus sign, followed by a sequence of digits.
49
50 Leading white-space characters in the string are skipped.
51
52 The strtof() function returns the converted value, if any.
53
54 If \a endptr is not \c NULL, a pointer to the character after the last
55 character used in the conversion is stored in the location referenced by
56 \a endptr.
57
58 If no conversion is performed, zero is returned and the value of
59 \a nptr is stored in the location referenced by \a endptr.
60
61 If the correct value would cause overflow, plus or minus \c INFINITY is
62 returned (according to the sign of the value), and \c ERANGE is stored
63 in \c errno. If the correct value would cause underflow, zero is
64 returned and \c ERANGE is stored in \c errno.
65 */
66
67 #include "stdio_private.h"
68
69 #define STRTOF
70
71 #include "conv_flt.c"
72
73 float
strtof(const char * nptr,char ** endptr)74 strtof (const char * nptr, char ** endptr)
75 {
76 int len = 0;
77 float flt;
78 unsigned char ret;
79
80 while (ISSPACE(nptr[len]))
81 len++;
82
83 ret = conv_flt(nptr, &len, INT_MAX, &flt, 0);
84 if (!ret) {
85 flt = 0.0;
86 len = 0;
87 }
88 if (endptr)
89 *endptr = (char *) nptr + len;
90 return flt;
91 }
92
