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/*
* Copyright (c) 2005 Martin Decky
* Copyright (c) 2008 Jiri Svoboda
* 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.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
/** @addtogroup libc
* @{
*/
/** @file
*/
#include <string.h>
#include <stdlib.h>
#include <limits.h>
#include <ctype.h>
#include <malloc.h>
#include <errno.h>
#include <string.h>
/** Byte mask consisting of lowest @n bits (out of 8) */
#define LO_MASK_8(n) ((uint8_t) ((1 << (n)) - 1))
/** Byte mask consisting of lowest @n bits (out of 32) */
#define LO_MASK_32(n) ((uint32_t) ((1 << (n)) - 1))
/** Byte mask consisting of highest @n bits (out of 8) */
#define HI_MASK_8(n) (~LO_MASK_8(8 - (n)))
/** Number of data bits in a UTF-8 continuation byte */
#define CONT_BITS 6
/** Decode a single character from a string.
*
* Decode a single character from a string of size @a size. Decoding starts
* at @a offset and this offset is moved to the beginning of the next
* character. In case of decoding error, offset generally advances at least
* by one. However, offset is never moved beyond size.
*
* @param str String (not necessarily NULL-terminated).
* @param offset Byte offset in string where to start decoding.
* @param size Size of the string (in bytes).
*
* @return Value of decoded character, U_SPECIAL on decoding error or
* NULL if attempt to decode beyond @a size.
*
*/
wchar_t str_decode(const char *str, size_t *offset, size_t size)
{
if (*offset + 1 > size)
return 0;
/* First byte read from string */
uint8_t b0 = (uint8_t) str[(*offset)++];
/* Determine code length */
unsigned int b0_bits; /* Data bits in first byte */
unsigned int cbytes; /* Number of continuation bytes */
if ((b0 & 0x80) == 0) {
/* 0xxxxxxx (Plain ASCII) */
b0_bits = 7;
cbytes = 0;
} else if ((b0 & 0xe0) == 0xc0) {
/* 110xxxxx 10xxxxxx */
b0_bits = 5;
cbytes = 1;
} else if ((b0 & 0xf0) == 0xe0) {
/* 1110xxxx 10xxxxxx 10xxxxxx */
b0_bits = 4;
cbytes = 2;
} else if ((b0 & 0xf8) == 0xf0) {
/* 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx */
b0_bits = 3;
cbytes = 3;
} else {
/* 10xxxxxx -- unexpected continuation byte */
return U_SPECIAL;
}
if (*offset + cbytes > size)
return U_SPECIAL;
wchar_t ch = b0 & LO_MASK_8(b0_bits);
/* Decode continuation bytes */
while (cbytes > 0) {
uint8_t b = (uint8_t) str[(*offset)++];
/* Must be 10xxxxxx */
if ((b & 0xc0) != 0x80)
return U_SPECIAL;
/* Shift data bits to ch */
ch = (ch << CONT_BITS) | (wchar_t) (b & LO_MASK_8(CONT_BITS));
cbytes--;
}
return ch;
}
/** Encode a single character to string representation.
*
* Encode a single character to string representation (i.e. UTF-8) and store
* it into a buffer at @a offset. Encoding starts at @a offset and this offset
* is moved to the position where the next character can be written to.
*
* @param ch Input character.
* @param str Output buffer.
* @param offset Byte offset where to start writing.
* @param size Size of the output buffer (in bytes).
*
* @return EOK if the character was encoded successfully, EOVERFLOW if there
* was not enough space in the output buffer or EINVAL if the character
* code was invalid.
*/
int chr_encode(const wchar_t ch, char *str, size_t *offset, size_t size)
{
if (*offset >= size)
return EOVERFLOW;
if (!chr_check(ch))
return EINVAL;
/* Unsigned version of ch (bit operations should only be done
on unsigned types). */
uint32_t cc = (uint32_t) ch;
/* Determine how many continuation bytes are needed */
unsigned int b0_bits; /* Data bits in first byte */
unsigned int cbytes; /* Number of continuation bytes */
if ((cc & ~LO_MASK_32(7)) == 0) {
b0_bits = 7;
cbytes = 0;
} else if ((cc & ~LO_MASK_32(11)) == 0) {
b0_bits = 5;
cbytes = 1;
} else if ((cc & ~LO_MASK_32(16)) == 0) {
b0_bits = 4;
cbytes = 2;
} else if ((cc & ~LO_MASK_32(21)) == 0) {
b0_bits = 3;
cbytes = 3;
} else {
/* Codes longer than 21 bits are not supported */
return EINVAL;
}
/* Check for available space in buffer */
if (*offset + cbytes >= size)
return EOVERFLOW;
/* Encode continuation bytes */
unsigned int i;
for (i = cbytes; i > 0; i--) {
str[*offset + i] = 0x80 | (cc & LO_MASK_32(CONT_BITS));
cc = cc >> CONT_BITS;
}
/* Encode first byte */
str[*offset] = (cc & LO_MASK_32(b0_bits)) | HI_MASK_8(8 - b0_bits - 1);
/* Advance offset */
*offset += cbytes + 1;
return EOK;
}
/** Check whether character is valid
*
* @return True if character is a valid Unicode code point.
*
*/
bool chr_check(const wchar_t ch)
{
if ((ch >= 0) && (ch <= 1114111))
return true;
return false;
}
/** Count the number of characters in the string, not including terminating 0.
*
* @param str String.
* @return Number of characters in string.
*/
size_t strlen(const char *str)
{
size_t counter = 0;
while (str[counter] != 0)
counter++;
return counter;
}
int strcmp(const char *a, const char *b)
{
int c = 0;
while (a[c] && b[c] && (!(a[c] - b[c])))
c++;
return (a[c] - b[c]);
}
int strncmp(const char *a, const char *b, size_t n)
{
size_t c = 0;
while (c < n && a[c] && b[c] && (!(a[c] - b[c])))
c++;
return ( c < n ? a[c] - b[c] : 0);
}
int stricmp(const char *a, const char *b)
{
int c = 0;
while (a[c] && b[c] && (!(tolower(a[c]) - tolower(b[c]))))
c++;
return (tolower(a[c]) - tolower(b[c]));
}
/** Return pointer to the first occurence of character c in string.
*
* @param str Scanned string.
* @param c Searched character (taken as one byte).
* @return Pointer to the matched character or NULL if it is not
* found in given string.
*/
char *strchr(const char *str, int c)
{
while (*str != '\0') {
if (*str == (char) c)
return (char *) str;
str++;
}
return NULL;
}
/** Return pointer to the last occurence of character c in string.
*
* @param str Scanned string.
* @param c Searched character (taken as one byte).
* @return Pointer to the matched character or NULL if it is not
* found in given string.
*/
char *strrchr(const char *str, int c)
{
char *retval = NULL;
while (*str != '\0') {
if (*str == (char) c)
retval = (char *) str;
str++;
}
return (char *) retval;
}
/** Convert string to a number.
* Core of strtol and strtoul functions.
*
* @param nptr Pointer to string.
* @param endptr If not NULL, function stores here pointer to the first
* invalid character.
* @param base Zero or number between 2 and 36 inclusive.
* @param sgn It's set to 1 if minus found.
* @return Result of conversion.
*/
static unsigned long
_strtoul(const char *nptr, char **endptr, int base, char *sgn)
{
unsigned char c;
unsigned long result = 0;
unsigned long a, b;
const char *str = nptr;
const char *tmpptr;
while (isspace(*str))
str++;
if (*str == '-') {
*sgn = 1;
++str;
} else if (*str == '+')
++str;
if (base) {
if ((base == 1) || (base > 36)) {
/* FIXME: set errno to EINVAL */
return 0;
}
if ((base == 16) && (*str == '0') && ((str[1] == 'x') ||
(str[1] == 'X'))) {
str += 2;
}
} else {
base = 10;
if (*str == '0') {
base = 8;
if ((str[1] == 'X') || (str[1] == 'x')) {
base = 16;
str += 2;
}
}
}
tmpptr = str;
while (*str) {
c = *str;
c = (c >= 'a' ? c - 'a' + 10 : (c >= 'A' ? c - 'A' + 10 :
(c <= '9' ? c - '0' : 0xff)));
if (c > base) {
break;
}
a = (result & 0xff) * base + c;
b = (result >> 8) * base + (a >> 8);
if (b > (ULONG_MAX >> 8)) {
/* overflow */
/* FIXME: errno = ERANGE*/
return ULONG_MAX;
}
result = (b << 8) + (a & 0xff);
++str;
}
if (str == tmpptr) {
/*
* No number was found => first invalid character is the first
* character of the string.
*/
/* FIXME: set errno to EINVAL */
str = nptr;
result = 0;
}
if (endptr)
*endptr = (char *) str;
if (nptr == str) {
/*FIXME: errno = EINVAL*/
return 0;
}
return result;
}
/** Convert initial part of string to long int according to given base.
* The number may begin with an arbitrary number of whitespaces followed by
* optional sign (`+' or `-'). If the base is 0 or 16, the prefix `0x' may be
* inserted and the number will be taken as hexadecimal one. If the base is 0
* and the number begin with a zero, number will be taken as octal one (as with
* base 8). Otherwise the base 0 is taken as decimal.
*
* @param nptr Pointer to string.
* @param endptr If not NULL, function stores here pointer to the first
* invalid character.
* @param base Zero or number between 2 and 36 inclusive.
* @return Result of conversion.
*/
long int strtol(const char *nptr, char **endptr, int base)
{
char sgn = 0;
unsigned long number = 0;
number = _strtoul(nptr, endptr, base, &sgn);
if (number > LONG_MAX) {
if ((sgn) && (number == (unsigned long) (LONG_MAX) + 1)) {
/* FIXME: set 0 to errno */
return number;
}
/* FIXME: set ERANGE to errno */
return (sgn ? LONG_MIN : LONG_MAX);
}
return (sgn ? -number : number);
}
/** Convert initial part of string to unsigned long according to given base.
* The number may begin with an arbitrary number of whitespaces followed by
* optional sign (`+' or `-'). If the base is 0 or 16, the prefix `0x' may be
* inserted and the number will be taken as hexadecimal one. If the base is 0
* and the number begin with a zero, number will be taken as octal one (as with
* base 8). Otherwise the base 0 is taken as decimal.
*
* @param nptr Pointer to string.
* @param endptr If not NULL, function stores here pointer to the first
* invalid character
* @param base Zero or number between 2 and 36 inclusive.
* @return Result of conversion.
*/
unsigned long strtoul(const char *nptr, char **endptr, int base)
{
char sgn = 0;
unsigned long number = 0;
number = _strtoul(nptr, endptr, base, &sgn);
return (sgn ? -number : number);
}
char *strcpy(char *dest, const char *src)
{
char *orig = dest;
while ((*(dest++) = *(src++)))
;
return orig;
}
char *strncpy(char *dest, const char *src, size_t n)
{
char *orig = dest;
while ((*(dest++) = *(src++)) && --n)
;
return orig;
}
char *strcat(char *dest, const char *src)
{
char *orig = dest;
while (*dest++)
;
--dest;
while ((*dest++ = *src++))
;
return orig;
}
char * strdup(const char *s1)
{
size_t len = strlen(s1) + 1;
void *ret = malloc(len);
if (ret == NULL)
return (char *) NULL;
return (char *) memcpy(ret, s1, len);
}
char *strtok(char *s, const char *delim)
{
static char *next;
return strtok_r(s, delim, &next);
}
char *strtok_r(char *s, const char *delim, char **next)
{
char *start, *end;
if (s == NULL)
s = *next;
/* Skip over leading delimiters. */
while (*s && (strchr(delim, *s) != NULL)) ++s;
start = s;
/* Skip over token characters. */
while (*s && (strchr(delim, *s) == NULL)) ++s;
end = s;
*next = (*s ? s + 1 : s);
if (start == end) {
return NULL; /* No more tokens. */
}
/* Overwrite delimiter with NULL terminator. */
*end = '\0';
return start;
}
/** @}
*/