/** memset - Fill a region of memory with the given value* @s: Pointer to the start of the area.* @c: The byte to fill the area with* @count: The size of the area.*/void *memset(void *s, int c, size_t count){char *xs = s;while (count--)*xs++ = c;return s;}

    /** memcpy - Copy one area of memory to another* @dest: Where to copy to* @src: Where to copy from* @count: The size of the area.*/void *memcpy(void *dest, const void *src, size_t count){char *tmp = dest;const char *s = src;while (count--)*tmp++ = *s++;return dest;}

    /** memmove - Copy one area of memory to another* @dest: Where to copy to* @src: Where to copy from* @count: The size of the area.* Unlike memcpy(), memmove() copes with overlapping areas.*/void *memmove(void *dest, const void *src, size_t count){char *tmp;const char *s;if (dest <= src) {tmp = dest;s = src;while (count--)*tmp++ = *s++;} else {tmp = dest;tmp += count;s = src;s += count;while (count--)*--tmp = *--s;}return dest;}

    /** memcmp - Compare two areas of memory* @cs: One area of memory* @ct: Another area of memory* @count: The size of the area.*/int memcmp(const void *cs, const void *ct, size_t count){const unsigned char *su1, *su2;int res = 0;for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)if ((res = *su1 - *su2) != 0)break;return res;}

    /** strcpy - Copy a %NUL terminated string* @dest: Where to copy the string to* @src: Where to copy the string from*/char *strcpy(char *dest, const char *src){char *tmp = dest;while ((*dest++ = *src++) != '\0');return tmp;}

    /** strncpy - Copy a length-limited, %NUL-terminated string* @dest: Where to copy the string to* @src: Where to copy the string from* @count: The maximum number of bytes to copy** The result is not %NUL-terminated if the source exceeds* @count bytes.** In the case where the length of @src is less than that of* count, the remainder of @dest will be padded with %NUL.*/char *strncpy(char *dest, const char *src, size_t count){char *tmp = dest;while (count) {if ((*tmp = *src) != 0)src++;tmp++;count--;}return dest;}

    /** strcat - Append one %NUL-terminated string to another* @dest: The string to be appended to* @src: The string to append to it*/char *strcat(char *dest, const char *src){char *tmp = dest;while (*dest)dest++;while ((*dest++ = *src++) != '\0');return tmp;}

    /** strncat - Append a length-limited, %NUL-terminated string to another* @dest: The string to be appended to* @src: The string to append to it* @count: The maximum numbers of bytes to copy** Note that in contrast to strncpy(), strncat() ensures the result is* terminated.*/char *strncat(char *dest, const char *src, size_t count){char *tmp = dest;if (count) {while (*dest)dest++;while ((*dest++ = *src++) != 0) {if (--count == 0) {*dest = '\0';break;}}}return tmp;}

    /** strcmp - Compare two strings* @cs: One string* @ct: Another string*/int strcmp(const char *cs, const char *ct){unsigned char c1, c2;while (1) {c1 = *cs++;c2 = *ct++;if (c1 != c2)return c1 < c2 ? -1 : 1;if (!c1)break;}return 0;}

    /** strncmp - Compare two length-limited strings* @cs: One string* @ct: Another string* @count: The maximum number of bytes to compare*/int strncmp(const char *cs, const char *ct, size_t count){unsigned char c1, c2;while (count) {c1 = *cs++;c2 = *ct++;if (c1 != c2)return c1 < c2 ? -1 : 1;if (!c1)break;count--;}return 0;}

    /** strchr - Find the first occurrence of a character in a string* @s: The string to be searched* @c: The character to search for*/char *strchr(const char *s, int c){for (; *s != (char)c; ++s)if (*s == '\0')return NULL;return (char *)s;}

    /** strlen - Find the length of a string* @s: The string to be sized*/size_t strlen(const char *s){const char *sc;for (sc = s; *sc != '\0'; ++sc);return sc - s;}

    /** strnlen - Find the length of a length-limited string* @s: The string to be sized* @count: The maximum number of bytes to search*/size_t strnlen(const char *s, size_t count){const char *sc;for (sc = s; count-- && *sc != '\0'; ++sc);return sc - s;}

    /** strsep - Split a string into tokens* @s: The string to be searched* @ct: The characters to search for** strsep() updates @s to point after the token, ready for the next call.*/char *strsep(char **s, const char *ct){char *sbegin = *s;char *end;if (sbegin == NULL)return NULL;end = strpbrk(sbegin, ct);if (end)*end++ = '\0';*s = end;return sbegin;}

    /** strstr - Find the first substring in a %NUL terminated string* @s1: The string to be searched* @s2: The string to search for*/char *strstr(const char *s1, const char *s2){int l1, l2;l2 = strlen(s2);if (!l2)return (char *)s1;l1 = strlen(s1);while (l1 >= l2) {l1--;if (!memcmp(s1, s2, l2))return (char *)s1;s1++;}return NULL;}