4.217.38 string.h
/* Copyright (c) 2002,2007 Marek Michalkiewicz
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* 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.
* Neither the name of the copyright holders nor the names of
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. */
/* $Id$ */
/*
string.h
Contributors:
Created by Marek Michalkiewicz <marekm@linux.org.pl>
*/
#ifndef _STRING_H_
#define _STRING_H_ 1
#ifndef __DOXYGEN__
#define __need_NULL
#define __need_size_t
#include <stddef.h>
#ifndef __ATTR_PURE__
#define __ATTR_PURE__ __attribute__((__pure__))
#endif
#ifndef __ATTR_CONST__
# define __ATTR_CONST__ __attribute__((__const__))
#endif
#endif /* !__DOXYGEN__ */
#ifdef __cplusplus
extern "C" {
#endif
/** \file */
/** \defgroup avr_string <string.h>: Strings
\code #include <string.h> \endcode
The string functions perform string operations on NULL terminated
strings.
\note If the strings you are working on resident in program space (flash),
you will need to use the string functions described in \ref avr_pgmspace. */
/** \ingroup avr_string
This macro finds the first (least significant) bit set in the
input value.
This macro is very similar to the function ffs() except that
it evaluates its argument at compile-time, so it should only
be applied to compile-time constant expressions where it will
reduce to a constant itself.
Application of this macro to expressions that are not constant
at compile-time is not recommended, and might result in a huge
amount of code generated.
\returns The _FFS() macro returns the position of the first
(least significant) bit set in the word val, or 0 if no bits are set.
The least significant bit is position 1. Only 16 bits of argument
are evaluted.
*/
#if defined(__DOXYGEN__)
#define _FFS(x)
#else /* !DOXYGEN */
#define _FFS(x) \
(1 \
+ (((x) & 1) == 0) \
+ (((x) & 3) == 0) \
+ (((x) & 7) == 0) \
+ (((x) & 017) == 0) \
+ (((x) & 037) == 0) \
+ (((x) & 077) == 0) \
+ (((x) & 0177) == 0) \
+ (((x) & 0377) == 0) \
+ (((x) & 0777) == 0) \
+ (((x) & 01777) == 0) \
+ (((x) & 03777) == 0) \
+ (((x) & 07777) == 0) \
+ (((x) & 017777) == 0) \
+ (((x) & 037777) == 0) \
+ (((x) & 077777) == 0) \
- (((x) & 0177777) == 0) * 16)
#endif /* DOXYGEN */
/** \ingroup avr_string
\fn int ffs(int val);
\brief This function finds the first (least significant) bit set in the input value.
\returns The ffs() function returns the position of the first
(least significant) bit set in the word val, or 0 if no bits are set.
The least significant bit is position 1.
\note For expressions that are constant at compile time, consider
using the \ref _FFS macro instead.
*/
extern int ffs(int __val) __ATTR_CONST__;
/** \ingroup avr_string
\fn int ffsl(long val);
\brief Same as ffs(), for an argument of type long. */
extern int ffsl(long __val) __ATTR_CONST__;
/** \ingroup avr_string
\fn int ffsll(long long val);
\brief Same as ffs(), for an argument of type long long. */
__extension__ extern int ffsll(long long __val) __ATTR_CONST__;
/** \ingroup avr_string
\fn void *memccpy(void *dest, const void *src, int val, size_t len)
\brief Copy memory area.
The memccpy() function copies no more than \p len bytes from memory
area \p src to memory area \p dest, stopping when the character \p val
is found.
\returns The memccpy() function returns a pointer to the next character
in \p dest after \p val, or NULL if \p val was not found in the first
\p len characters of \p src. */
extern void *memccpy(void *, const void *, int, size_t);
/** \ingroup avr_string
\fn void *memchr(const void *src, int val, size_t len)
\brief Scan memory for a character.
The memchr() function scans the first len bytes of the memory area pointed
to by src for the character val. The first byte to match val (interpreted
as an unsigned character) stops the operation.
\returns The memchr() function returns a pointer to the matching byte or
NULL if the character does not occur in the given memory area. */
extern void *memchr(const void *, int, size_t) __ATTR_PURE__;
/** \ingroup avr_string
\fn int memcmp(const void *s1, const void *s2, size_t len)
\brief Compare memory areas
The memcmp() function compares the first len bytes of the memory areas s1
and s2. The comparision is performed using unsigned char operations.
\returns The memcmp() function returns an integer less than, equal to, or
greater than zero if the first len bytes of s1 is found, respectively, to be
less than, to match, or be greater than the first len bytes of s2.
\note Be sure to store the result in a 16 bit variable since you may get
incorrect results if you use an unsigned char or char due to truncation.
\warning This function is not -mint8 compatible, although if you only care
about testing for equality, this function should be safe to use. */
extern int memcmp(const void *, const void *, size_t) __ATTR_PURE__;
/** \ingroup avr_string
\fn void *memcpy(void *dest, const void *src, size_t len)
\brief Copy a memory area.
The memcpy() function copies len bytes from memory area src to memory area
dest. The memory areas may not overlap. Use memmove() if the memory
areas do overlap.
\returns The memcpy() function returns a pointer to dest. */
extern void *memcpy(void *, const void *, size_t);
/** \ingroup avr_string
\fn void *memmem(const void *s1, size_t len1, const void *s2, size_t len2)
The memmem() function finds the start of the first occurrence of the
substring \p s2 of length \p len2 in the memory area \p s1 of length
\p len1.
\return The memmem() function returns a pointer to the beginning of
the substring, or \c NULL if the substring is not found. If \p len2
is zero, the function returns \p s1. */
extern void *memmem(const void *, size_t, const void *, size_t) __ATTR_PURE__;
/** \ingroup avr_string
\fn void *memmove(void *dest, const void *src, size_t len)
\brief Copy memory area.
The memmove() function copies len bytes from memory area src to memory area
dest. The memory areas may overlap.
\returns The memmove() function returns a pointer to dest. */
extern void *memmove(void *, const void *, size_t);
/** \ingroup avr_string
\fn void *memrchr(const void *src, int val, size_t len)
The memrchr() function is like the memchr() function, except that it
searches backwards from the end of the \p len bytes pointed to by \p
src instead of forwards from the front. (Glibc, GNU extension.)
\return The memrchr() function returns a pointer to the matching
byte or \c NULL if the character does not occur in the given memory
area. */
extern void *memrchr(const void *, int, size_t) __ATTR_PURE__;
/** \ingroup avr_string
\fn void *memset(void *dest, int val, size_t len)
\brief Fill memory with a constant byte.
The memset() function fills the first len bytes of the memory area pointed
to by dest with the constant byte val.
\returns The memset() function returns a pointer to the memory area dest. */
extern void *memset(void *, int, size_t);
/** \ingroup avr_string
\fn char *strcat(char *dest, const char *src)
\brief Concatenate two strings.
The strcat() function appends the src string to the dest string
overwriting the '\\0' character at the end of dest, and then adds a
terminating '\\0' character. The strings may not overlap, and the dest
string must have enough space for the result.
\returns The strcat() function returns a pointer to the resulting string
dest. */
extern char *strcat(char *, const char *);
/** \ingroup avr_string
\fn char *strchr(const char *src, int val)
\brief Locate character in string.
The strchr() function returns a pointer to the first occurrence of
the character \p val in the string \p src.
Here "character" means "byte" - these functions do not work with
wide or multi-byte characters.
\returns The strchr() function returns a pointer to the matched
character or \c NULL if the character is not found. */
extern char *strchr(const char *, int) __ATTR_PURE__;
/** \ingroup avr_string
\fn char *strchrnul(const char *s, int c)
The strchrnul() function is like strchr() except that if \p c is not
found in \p s, then it returns a pointer to the null byte at the end
of \p s, rather than \c NULL. (Glibc, GNU extension.)
\return The strchrnul() function returns a pointer to the matched
character, or a pointer to the null byte at the end of \p s (i.e.,
\c s+strlen(s)) if the character is not found. */
extern char *strchrnul(const char *, int) __ATTR_PURE__;
/** \ingroup avr_string
\fn int strcmp(const char *s1, const char *s2)
\brief Compare two strings.
The strcmp() function compares the two strings \p s1 and \p s2.
\returns The strcmp() function returns an integer less than, equal
to, or greater than zero if \p s1 is found, respectively, to be less
than, to match, or be greater than \p s2. A consequence of the
ordering used by strcmp() is that if \p s1 is an initial substring
of \p s2, then \p s1 is considered to be "less than" \p s2. */
extern int strcmp(const char *, const char *) __ATTR_PURE__;
/** \ingroup avr_string
\fn char *strcpy(char *dest, const char *src)
\brief Copy a string.
The strcpy() function copies the string pointed to by src (including the
terminating '\\0' character) to the array pointed to by dest. The strings
may not overlap, and the destination string dest must be large enough to
receive the copy.
\returns The strcpy() function returns a pointer to the destination
string dest.
\note If the destination string of a strcpy() is not large enough (that
is, if the programmer was stupid/lazy, and failed to check the size before
copying) then anything might happen. Overflowing fixed length strings is
a favourite cracker technique. */
extern char *strcpy(char *, const char *);
/** \ingroup avr_string
\fn int strcasecmp(const char *s1, const char *s2)
\brief Compare two strings ignoring case.
The strcasecmp() function compares the two strings \p s1 and \p s2,
ignoring the case of the characters.
\returns The strcasecmp() function returns an integer less than,
equal to, or greater than zero if \p s1 is found, respectively, to
be less than, to match, or be greater than \p s2. A consequence of
the ordering used by strcasecmp() is that if \p s1 is an initial
substring of \p s2, then \p s1 is considered to be "less than"
\p s2. */
extern int strcasecmp(const char *, const char *) __ATTR_PURE__;
/** \ingroup avr_string
\fn char *strcasestr(const char *s1, const char *s2)
The strcasestr() function finds the first occurrence of the
substring \p s2 in the string \p s1. This is like strstr(), except
that it ignores case of alphabetic symbols in searching for the
substring. (Glibc, GNU extension.)
\return The strcasestr() function returns a pointer to the beginning
of the substring, or \c NULL if the substring is not found. If \p s2
points to a string of zero length, the function returns \p s1. */
extern char *strcasestr(const char *, const char *) __ATTR_PURE__;
/** \ingroup avr_string
\fn size_t strcspn(const char *s, const char *reject)
The strcspn() function calculates the length of the initial segment
of \p s which consists entirely of characters not in \p reject.
\return The strcspn() function returns the number of characters in
the initial segment of \p s which are not in the string \p reject.
The terminating zero is not considered as a part of string. */
extern size_t strcspn(const char *__s, const char *__reject) __ATTR_PURE__;
/** \ingroup avr_string
\fn char *strdup(const char *s1)
\brief Duplicate a string.
The strdup() function allocates memory and copies into it the string
addressed by s1, including the terminating null character.
\warning The strdup() function calls malloc() to allocate the memory
for the duplicated string! The user is responsible for freeing the
memory by calling free().
\returns The strdup() function returns a pointer to the resulting string
dest. If malloc() cannot allocate enough storage for the string, strdup()
will return NULL.
\warning Be sure to check the return value of the strdup() function to
make sure that the function has succeeded in allocating the memory!
*/
extern char *strdup(const char *s1);
/** \ingroup avr_string
\fn size_t strlcat(char *dst, const char *src, size_t siz)
\brief Concatenate two strings.
Appends \p src to string \p dst of size \p siz (unlike strncat(),
\p siz is the full size of \p dst, not space left). At most \p siz-1
characters will be copied. Always NULL terminates (unless \p siz <=
\p strlen(dst)).
\returns The strlcat() function returns strlen(src) + MIN(siz,
strlen(initial dst)). If retval >= siz, truncation occurred. */
extern size_t strlcat(char *, const char *, size_t);
/** \ingroup avr_string
\fn size_t strlcpy(char *dst, const char *src, size_t siz)
\brief Copy a string.
Copy \p src to string \p dst of size \p siz. At most \p siz-1
characters will be copied. Always NULL terminates (unless \p siz == 0).
\returns The strlcpy() function returns strlen(src). If retval >= siz,
truncation occurred. */
extern size_t strlcpy(char *, const char *, size_t);
/** \ingroup avr_string
\fn size_t strlen(const char *src)
\brief Calculate the length of a string.
The strlen() function calculates the length of the string src, not
including the terminating '\\0' character.
\returns The strlen() function returns the number of characters in
src. */
extern size_t strlen(const char *) __ATTR_PURE__;
/** \ingroup avr_string
\fn char *strlwr(char *s)
\brief Convert a string to lower case.
The strlwr() function will convert a string to lower case. Only the upper
case alphabetic characters [A .. Z] are converted. Non-alphabetic
characters will not be changed.
\returns The strlwr() function returns a pointer to the converted
string. */
extern char *strlwr(char *);
/** \ingroup avr_string
\fn char *strncat(char *dest, const char *src, size_t len)
\brief Concatenate two strings.
The strncat() function is similar to strcat(), except that only the first
n characters of src are appended to dest.
\returns The strncat() function returns a pointer to the resulting string
dest. */
extern char *strncat(char *, const char *, size_t);
/** \ingroup avr_string
\fn int strncmp(const char *s1, const char *s2, size_t len)
\brief Compare two strings.
The strncmp() function is similar to strcmp(), except it only compares the
first (at most) n characters of s1 and s2.
\returns The strncmp() function returns an integer less than, equal to, or
greater than zero if s1 (or the first n bytes thereof) is found,
respectively, to be less than, to match, or be greater than s2. */
extern int strncmp(const char *, const char *, size_t) __ATTR_PURE__;
/** \ingroup avr_string
\fn char *strncpy(char *dest, const char *src, size_t len)
\brief Copy a string.
The strncpy() function is similar to strcpy(), except that not more than n
bytes of src are copied. Thus, if there is no null byte among the first n
bytes of src, the result will not be null-terminated.
In the case where the length of src is less than that of n, the remainder
of dest will be padded with nulls.
\returns The strncpy() function returns a pointer to the destination
string dest. */
extern char *strncpy(char *, const char *, size_t);
/** \ingroup avr_string
\fn int strncasecmp(const char *s1, const char *s2, size_t len)
\brief Compare two strings ignoring case.
The strncasecmp() function is similar to strcasecmp(), except it
only compares the first \p len characters of \p s1.
\returns The strncasecmp() function returns an integer less than,
equal to, or greater than zero if \p s1 (or the first \p len bytes
thereof) is found, respectively, to be less than, to match, or be
greater than \p s2. A consequence of the ordering used by
strncasecmp() is that if \p s1 is an initial substring of \p s2,
then \p s1 is considered to be "less than" \p s2. */
extern int strncasecmp(const char *, const char *, size_t) __ATTR_PURE__;
/** \ingroup avr_string
\fn size_t strnlen(const char *src, size_t len)
\brief Determine the length of a fixed-size string.
The strnlen function returns the number of characters in the string
pointed to by src, not including the terminating '\\0' character, but at
most len. In doing this, strnlen looks only at the first len characters at
src and never beyond src+len.
\returns The strnlen function returns strlen(src), if that is less than
len, or len if there is no '\\0' character among the first len
characters pointed to by src. */
extern size_t strnlen(const char *, size_t) __ATTR_PURE__;
/** \ingroup avr_string
\fn char *strpbrk(const char *s, const char *accept)
The strpbrk() function locates the first occurrence in the string
\p s of any of the characters in the string \p accept.
\return The strpbrk() function returns a pointer to the character
in \p s that matches one of the characters in \p accept, or \c NULL
if no such character is found. The terminating zero is not
considered as a part of string: if one or both args are empty, the
result will be \c NULL. */
extern char *strpbrk(const char *__s, const char *__accept) __ATTR_PURE__;
/** \ingroup avr_string
\fn char *strrchr(const char *src, int val)
\brief Locate character in string.
The strrchr() function returns a pointer to the last occurrence of the
character val in the string src.
Here "character" means "byte" - these functions do not work with wide or
multi-byte characters.
\returns The strrchr() function returns a pointer to the matched character
or NULL if the character is not found. */
extern char *strrchr(const char *, int) __ATTR_PURE__;
/** \ingroup avr_string
\fn char *strrev(char *s)
\brief Reverse a string.
The strrev() function reverses the order of the string.
\returns The strrev() function returns a pointer to the beginning of the
reversed string. */
extern char *strrev(char *);
/** \ingroup avr_string
\fn char *strsep(char **sp, const char *delim)
\brief Parse a string into tokens.
The strsep() function locates, in the string referenced by \p *sp,
the first occurrence of any character in the string \p delim (or the
terminating '\\0' character) and replaces it with a '\\0'. The
location of the next character after the delimiter character (or \c
NULL, if the end of the string was reached) is stored in \p *sp. An
``empty'' field, i.e. one caused by two adjacent delimiter
characters, can be detected by comparing the location referenced by
the pointer returned in \p *sp to '\\0'.
\return The strsep() function returns a pointer to the original
value of \p *sp. If \p *sp is initially \c NULL, strsep() returns
\c NULL. */
extern char *strsep(char **, const char *);
/** \ingroup avr_string
\fn size_t strspn(const char *s, const char *accept)
The strspn() function calculates the length of the initial segment
of \p s which consists entirely of characters in \p accept.
\return The strspn() function returns the number of characters in
the initial segment of \p s which consist only of characters from \p
accept. The terminating zero is not considered as a part of string. */
extern size_t strspn(const char *__s, const char *__accept) __ATTR_PURE__;
/** \ingroup avr_string
\fn char *strstr(const char *s1, const char *s2)
\brief Locate a substring.
The strstr() function finds the first occurrence of the substring \p
s2 in the string \p s1. The terminating '\\0' characters are not
compared.
\returns The strstr() function returns a pointer to the beginning of
the substring, or \c NULL if the substring is not found. If \p s2
points to a string of zero length, the function returns \p s1. */
extern char *strstr(const char *, const char *) __ATTR_PURE__;
/** \ingroup avr_string
\fn char *strtok(char *s, const char *delim)
\brief Parses the string s into tokens.
strtok parses the string s into tokens. The first call to strtok
should have s as its first argument. Subsequent calls should have
the first argument set to NULL. If a token ends with a delimiter, this
delimiting character is overwritten with a '\\0' and a pointer to the next
character is saved for the next call to strtok. The delimiter string
delim may be different for each call.
\returns The strtok() function returns a pointer to the next token or
NULL when no more tokens are found.
\note strtok() is NOT reentrant. For a reentrant version of this function
see \c strtok_r().
*/
extern char *strtok(char *, const char *);
/** \ingroup avr_string
\fn char *strtok_r(char *string, const char *delim, char **last)
\brief Parses string into tokens.
strtok_r parses string into tokens. The first call to strtok_r
should have string as its first argument. Subsequent calls should have
the first argument set to NULL. If a token ends with a delimiter, this
delimiting character is overwritten with a '\\0' and a pointer to the next
character is saved for the next call to strtok_r. The delimiter string
\p delim may be different for each call. \p last is a user allocated char*
pointer. It must be the same while parsing the same string. strtok_r is
a reentrant version of strtok().
\returns The strtok_r() function returns a pointer to the next token or
NULL when no more tokens are found. */
extern char *strtok_r(char *, const char *, char **);
/** \ingroup avr_string
\fn char *strupr(char *s)
\brief Convert a string to upper case.
The strupr() function will convert a string to upper case. Only the lower
case alphabetic characters [a .. z] are converted. Non-alphabetic
characters will not be changed.
\returns The strupr() function returns a pointer to the converted
string. The pointer is the same as that passed in since the operation is
perform in place. */
extern char *strupr(char *);
#ifndef __DOXYGEN__
/* libstdc++ compatibility, dummy declarations */
extern int strcoll(const char *s1, const char *s2);
extern char *strerror(int errnum);
extern size_t strxfrm(char *dest, const char *src, size_t n);
#endif /* !__DOXYGEN__ */
#ifdef __cplusplus
}
#endif
#endif /* _STRING_H_ */