FFmpeg
strtod.c
Go to the documentation of this file.
1 /*
2  * C99-compatible strtod() implementation
3  * Copyright (c) 2012 Ronald S. Bultje <rsbultje@gmail.com>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include <limits.h>
23 #include <stdlib.h>
24 
25 #include "libavutil/avstring.h"
26 #include "libavutil/mathematics.h"
27 
28 static const char *check_nan_suffix(const char *s)
29 {
30  const char *start = s;
31 
32  if (*s++ != '(')
33  return start;
34 
35  while ((*s >= 'a' && *s <= 'z') || (*s >= 'A' && *s <= 'Z') ||
36  (*s >= '0' && *s <= '9') || *s == '_')
37  s++;
38 
39  return *s == ')' ? s + 1 : start;
40 }
41 
42 #undef strtod
43 double strtod(const char *, char **);
44 
45 double avpriv_strtod(const char *nptr, char **endptr)
46 {
47  const char *end;
48  double res;
49 
50  /* Skip leading spaces */
51  while (av_isspace(*nptr))
52  nptr++;
53 
54  if (!av_strncasecmp(nptr, "infinity", 8)) {
55  end = nptr + 8;
56  res = INFINITY;
57  } else if (!av_strncasecmp(nptr, "inf", 3)) {
58  end = nptr + 3;
59  res = INFINITY;
60  } else if (!av_strncasecmp(nptr, "+infinity", 9)) {
61  end = nptr + 9;
62  res = INFINITY;
63  } else if (!av_strncasecmp(nptr, "+inf", 4)) {
64  end = nptr + 4;
65  res = INFINITY;
66  } else if (!av_strncasecmp(nptr, "-infinity", 9)) {
67  end = nptr + 9;
68  res = -INFINITY;
69  } else if (!av_strncasecmp(nptr, "-inf", 4)) {
70  end = nptr + 4;
71  res = -INFINITY;
72  } else if (!av_strncasecmp(nptr, "nan", 3)) {
73  end = check_nan_suffix(nptr + 3);
74  res = NAN;
75  } else if (!av_strncasecmp(nptr, "+nan", 4) ||
76  !av_strncasecmp(nptr, "-nan", 4)) {
77  end = check_nan_suffix(nptr + 4);
78  res = NAN;
79  } else if (!av_strncasecmp(nptr, "0x", 2) ||
80  !av_strncasecmp(nptr, "-0x", 3) ||
81  !av_strncasecmp(nptr, "+0x", 3)) {
82  /* FIXME this doesn't handle exponents, non-integers (float/double)
83  * and numbers too large for long long */
84  res = strtoll(nptr, (char **)&end, 16);
85  } else {
86  res = strtod(nptr, (char **)&end);
87  }
88 
89  if (endptr)
90  *endptr = (char *)end;
91 
92  return res;
93 }
static av_const int av_isspace(int c)
Locale-independent conversion of ASCII isspace.
Definition: avstring.h:222
int av_strncasecmp(const char *a, const char *b, size_t n)
Locale-independent case-insensitive compare.
Definition: avstring.c:223
double avpriv_strtod(const char *nptr, char **endptr)
Definition: strtod.c:45
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
double strtod(const char *, char **)
#define NAN
Definition: mathematics.h:64
#define s(width, name)
Definition: cbs_vp9.c:257
void INT64 start
Definition: avisynth_c.h:766
static const char * check_nan_suffix(const char *s)
Definition: strtod.c:28
#define INFINITY
Definition: mathematics.h:67