Merge branch 'master' into nuttx-merge-5447

This commit is contained in:
px4dev
2013-01-11 00:39:22 -08:00
128 changed files with 12693 additions and 1007 deletions
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############################################################################
# libc/math/Make.defs
#
# Copyright (C) 2012 Gregory Nutt. All rights reserved.
# Author: Gregory Nutt <gnutt@nuttx.org>
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in
# the documentation and/or other materials provided with the
# distribution.
# 3. Neither the name NuttX nor the names of its contributors may be
# used to endorse or promote products derived from this software
# without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
# OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
#
############################################################################
ifeq ($(CONFIG_LIBM),y)
# Add the floating point math C files to the build
CSRCS += lib_acosf.c lib_asinf.c lib_atan2f.c lib_atanf.c lib_ceilf.c lib_cosf.c
CSRCS += lib_coshf.c lib_expf.c lib_fabsf.c lib_floorf.c lib_fmodf.c lib_frexpf.c
CSRCS += lib_ldexpf.c lib_logf.c lib_log10f.c lib_log2f.c lib_modff.c lib_powf.c
CSRCS += lib_roundf.c lib_sinf.c lib_sinhf.c lib_sqrtf.c lib_tanf.c lib_tanhf.c
CSRCS += lib_acos.c lib_asin.c lib_atan.c lib_atan2.c lib_ceil.c lib_cos.c
CSRCS += lib_cosh.c lib_exp.c lib_fabs.c lib_floor.c lib_fmod.c lib_frexp.c
CSRCS += lib_ldexp.c lib_log.c lib_log10.c lib_log2.c lib_modf.c lib_pow.c
CSRCS += lib_round.c lib_sin.c lib_sinh.c lib_sqrt.c lib_tan.c lib_tanh.c
CSRCS += lib_acosl.c lib_asinl.c lib_atan2l.c lib_atanl.c lib_ceill.c lib_cosl.c
CSRCS += lib_coshl.c lib_expl.c lib_fabsl.c lib_floorl.c lib_fmodl.c lib_frexpl.c
CSRCS += lib_ldexpl.c lib_logl.c lib_log10l.c lib_log2l.c lib_modfl.c lib_powl.c
CSRCS += lib_roundl.c lib_sinl.c lib_sinhl.c lib_sqrtl.c lib_tanl.c lib_tanhl.c
CSRCS += lib_libexpi.c lib_libsqrtapprox.c
# Add the floating point math directory to the build
DEPPATH += --dep-path math
VPATH += :math
endif
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/************************************************************************
* lib/math/lib_round.c
*
* This file is a part of NuttX:
*
* Copyright (C) 2012 Gregory Nutt. All rights reserved.
* (C) 2012 Petteri Aimonen <jpa@nx.mail.kapsi.fi>
*
************************************************************************/
/************************************************************************
* Included Files
************************************************************************/
#include <nuttx/config.h>
#include <nuttx/compiler.h>
#include <math.h>
/************************************************************************
* Public Functions
************************************************************************/
#ifdef CONFIG_HAVE_DOUBLE
double round(double x)
{
double f = modf(x, &x);
if (x <= 0.0 && f <= -0.5)
{
x -= 1.0;
}
if (x >= 0.0 && f >= 0.5)
{
x += 1.0;
}
return x;
}
#endif
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/************************************************************************
* lib/math/lib_roundf.c
*
* This file is a part of NuttX:
*
* Copyright (C) 2012 Gregory Nutt. All rights reserved.
* (C) 2012 Petteri Aimonen <jpa@nx.mail.kapsi.fi>
*
************************************************************************/
/************************************************************************
* Included Files
************************************************************************/
#include <nuttx/config.h>
#include <nuttx/compiler.h>
#include <math.h>
/************************************************************************
* Public Functions
************************************************************************/
float roundf(float x)
{
float f = modff(x, &x);
if (x <= 0.0f && f <= -0.5f)
{
x -= 1.0f;
}
if (x >= 0.0f && f >= 0.5f)
{
x += 1.0f;
}
return x;
}
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/************************************************************************
* lib/math/lib_round.c
*
* This file is a part of NuttX:
*
* Copyright (C) 2012 Gregory Nutt. All rights reserved.
* (C) 2012 Petteri Aimonen <jpa@nx.mail.kapsi.fi>
*
************************************************************************/
/************************************************************************
* Included Files
************************************************************************/
#include <nuttx/config.h>
#include <nuttx/compiler.h>
#include <math.h>
/************************************************************************
* Public Functions
************************************************************************/
#ifdef CONFIG_HAVE_LONG_DOUBLE
long double roundl(long double x)
{
long double f = modfl(x, &x);
if (x <= 0.0 && f <= -0.5)
{
x -= 1.0;
}
if (x >= 0.0 && f >= 0.5)
{
x += 1.0;
}
return x;
}
#endif
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/****************************************************************************
* libc/stdlib/lib_rand.c
*
* Copyright (C) 2007, 2011 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <sys/types.h>
#include <stdlib.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* First, second, and thired order congruential generators are supported */
#ifndef CONFIG_LIB_RAND_ORDER
# define CONFIG_LIB_RAND_ORDER 1
#endif
#if CONFIG_LIB_RAND_ORDER > 3
# undef CONFIG_LIB_RAND_ORDER
# define CONFIG_LIB_RAND_ORDER 3
#endif
/* Values needed by the random number generator */
#define RND1_CONSTK 470001
#define RND1_CONSTP 999563
#define RND2_CONSTK1 366528
#define RND2_CONSTK2 508531
#define RND2_CONSTP 998917
#define RND3_CONSTK1 360137
#define RND3_CONSTK2 519815
#define RND3_CONSTK3 616087
#define RND3_CONSTP 997783
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static unsigned int nrand(unsigned int nLimit);
/* First order congruential generators */
static inline unsigned long fgenerate1(void);
#if (CONFIG_LIB_RAND_ORDER == 1)
static double_t frand1(void);
#endif
/* Second order congruential generators */
#if (CONFIG_LIB_RAND_ORDER > 1)
static inline unsigned long fgenerate2(void);
#if (CONFIG_LIB_RAND_ORDER == 2)
static double_t frand2(void);
#endif
/* Third order congruential generators */
#if (CONFIG_LIB_RAND_ORDER > 2)
static inline unsigned long fgenerate3(void);
static double_t frand3(void);
#endif
#endif
/****************************************************************************
* Private Data
****************************************************************************/
static unsigned long g_randint1;
#if (CONFIG_LIB_RAND_ORDER > 1)
static unsigned long g_randint2;
#if (CONFIG_LIB_RAND_ORDER > 2)
static unsigned long g_randint3;
#endif
#endif
/****************************************************************************
* Private Functions
****************************************************************************/
static unsigned int nrand(unsigned int nLimit)
{
unsigned long result;
double_t ratio;
/* Loop to be sure a legal random number is generated */
do
{
/* Get a random integer in the requested range */
#if (CONFIG_LIB_RAND_ORDER == 1)
ratio = frand1();
#elif (CONFIG_LIB_RAND_ORDER == 2)
ratio = frand2();
#else /* if (CONFIG_LIB_RAND_ORDER > 2) */
ratio = frand3();
#endif
/* Then, produce the return-able value */
result = (unsigned long)(((double_t)nLimit) * ratio);
}
while (result >= (unsigned long)nLimit);
return (unsigned int)result;
}
/* First order congruential generators */
static inline unsigned long fgenerate1(void)
{
unsigned long randint;
/* First order congruential generator. One may be added to the result of the
* generated value to avoid the value zero. This would be fatal for the
* first order random number generator.
*/
randint = (RND1_CONSTK * g_randint1) % RND1_CONSTP;
g_randint1 = (randint == 0 ? 1 : randint);
return randint;
}
#if (CONFIG_LIB_RAND_ORDER == 1)
static double_t frand1(void)
{
/* First order congruential generator. */
unsigned long randint = fgenerate1();
/* Construct an floating point value in the range from 0.0 up to 1.0 */
return ((double_t)randint) / ((double_t)RND1_CONSTP);
}
#endif
/* Second order congruential generators */
#if (CONFIG_LIB_RAND_ORDER > 1)
static inline unsigned long fgenerate2(void)
{
unsigned long randint;
/* Second order congruential generator. */
randint = (RND2_CONSTK1 * g_randint1 +
RND2_CONSTK2 * g_randint2) % RND2_CONSTP;
g_randint2 = g_randint1;
g_randint1 = randint;
/* We cannot permit both values to become zero. That would be fatal for the
* second order random number generator.
*/
if (g_randint2 == 0 && g_randint1 == 0)
{
g_randint2 = 1;
}
return randint;
}
#if (CONFIG_LIB_RAND_ORDER == 2)
static double_t frand2(void)
{
/* Second order congruential generator */
unsigned long randint = fgenerate2();
/* Construct an floating point value in the range from 0.0 up to 1.0 */
return ((double_t)randint) / ((double_t)RND2_CONSTP);
}
#endif
/* Third order congruential generators */
#if (CONFIG_LIB_RAND_ORDER > 2)
static inline unsigned long fgenerate3(void)
{
unsigned long randint;
/* Third order congruential generator. */
randint = (RND3_CONSTK1 * g_randint1 +
RND3_CONSTK2 * g_randint2 +
RND3_CONSTK2 * g_randint3) % RND3_CONSTP;
g_randint3 = g_randint2;
g_randint2 = g_randint1;
g_randint1 = randint;
/* We cannot permit all three values to become zero. That would be fatal for the
* third order random number generator.
*/
if (g_randint3 == 0 && g_randint2 == 0 && g_randint1 == 0)
{
g_randint3 = 1;
}
return randint;
}
static double_t frand3(void)
{
/* Third order congruential generator */
unsigned long randint = fgenerate3();
/* Construct an floating point value in the range from 0.0 up to 1.0 */
return ((double_t)randint) / ((double_t)RND3_CONSTP);
}
#endif
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Function: srand, rand
****************************************************************************/
void srand(unsigned int seed)
{
g_randint1 = seed;
#if (CONFIG_LIB_RAND_ORDER > 1)
g_randint2 = seed;
(void)fgenerate1();
#if (CONFIG_LIB_RAND_ORDER > 2)
g_randint3 = seed;
(void)fgenerate2();
#endif
#endif
}
int rand(void)
{
return (int)nrand(32768);
}
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/************************************************************
* libc/string/lib_memcmp.c
*
* Copyright (C) 2007, 2011-2012 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
************************************************************/
/************************************************************
* Compilation Switches
************************************************************/
/************************************************************
* Included Files
************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <string.h>
/************************************************************
* Global Functions
************************************************************/
#ifndef CONFIG_ARCH_MEMCMP
int memcmp(FAR const void *s1, FAR const void *s2, size_t n)
{
unsigned char *p1 = (unsigned char *)s1;
unsigned char *p2 = (unsigned char *)s2;
while (n-- > 0)
{
if (*p1 < *p2)
{
return -1;
}
else if (*p1 > *p2)
{
return 1;
}
p1++;
p2++;
}
return 0;
}
#endif
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/************************************************************
* libc/string/lib_memmove.c
*
* Copyright (C) 2007, 2011 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
************************************************************/
/************************************************************
* Compilation Switches
************************************************************/
/************************************************************
* Included Files
************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <string.h>
/************************************************************
* Global Functions
************************************************************/
#ifndef CONFIG_ARCH_MEMMOVE
FAR void *memmove(FAR void *dest, FAR const void *src, size_t count)
{
char *tmp, *s;
if (dest <= src)
{
tmp = (char*) dest;
s = (char*) src;
while (count--)
{
*tmp++ = *s++;
}
}
else
{
tmp = (char*) dest + count;
s = (char*) src + count;
while (count--)
{
*--tmp = *--s;
}
}
return dest;
}
#endif
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/****************************************************************************
* libc/string/lib_strstr.c
*
* Copyright (C) 2012 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use str source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions str binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer str
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <string.h>
#include <ctype.h>
/****************************************************************************
* Private Functions
****************************************************************************/
static FAR char *strcasechr(FAR const char *s, int uc)
{
register char ch;
if (s)
{
for (; *s; s++)
{
ch = *s;
if (toupper(ch) == uc)
{
return (FAR char*)s;
}
}
}
return NULL;
}
/****************************************************************************
* Global Functions
****************************************************************************/
FAR char *strcasestr(FAR const char *str, FAR const char *substr)
{
const char *candidate; /* Candidate in str with matching start character */
char ch; /* First character of the substring */
int len; /* The length of the substring */
/* Special case the empty substring */
len = strlen(substr);
ch = *substr;
if (!ch)
{
/* We'll say that an empty substring matches at the beginning of
* the string
*/
return (char*)str;
}
/* Search for the substring */
candidate = str;
ch = toupper(ch);
for (;;)
{
/* strcasechr() will return a pointer to the next occurrence of the
* character ch in the string (ignoring case)
*/
candidate = strcasechr(candidate, ch);
if (!candidate || strlen(candidate) < len)
{
/* First character of the substring does not appear in the string
* or the remainder of the string is not long enough to contain the
* substring.
*/
return NULL;
}
/* Check if this is the beginning of a matching substring (ignoring case) */
if (strncasecmp(candidate, substr, len) == 0)
{
/* Yes.. return the pointer to the first occurrence of the matching
* substring.
*/
return (char*)candidate;
}
/* No, find the next candidate after this one */
candidate++;
}
/* Won't get here, but some compilers might complain. Others might complain
* about this code being unreachable too.
*/
return NULL;
}
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/****************************************************************************
* libc/string/lib_strstr.c
*
* Copyright (C) 2009, 2011 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use str source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions str binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer str
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <string.h>
/****************************************************************************
* Global Functions
****************************************************************************/
char *strstr(const char *str, const char *substr)
{
const char *candidate; /* Candidate in str with matching start character */
char ch; /* First character of the substring */
int len; /* The length of the substring */
/* Special case the empty substring */
len = strlen(substr);
ch = *substr;
if (!ch)
{
/* We'll say that an empty substring matches at the beginning of
* the string
*/
return (char*)str;
}
/* Search for the substring */
candidate = str;
for (;;)
{
/* strchr() will return a pointer to the next occurrence of the
* character ch in the string
*/
candidate = strchr(candidate, ch);
if (!candidate || strlen(candidate) < len)
{
/* First character of the substring does not appear in the string
* or the remainder of the string is not long enough to contain the
* substring.
*/
return NULL;
}
/* Check if this is the beginning of a matching substring */
if (strncmp(candidate, substr, len) == 0)
{
return (char*)candidate;
}
/* No, find the next candidate after this one */
candidate++;
}
/* Won't get here, but some compilers might complain. Other compilers
* might complain about this code being unreachable too.
*/
return NULL;
}