11 extern int strlen(const char *string);
12 extern int strcmp(const char *str1, const char *str2);
13 extern int strncmp(const char *str1, const char *str2, size_t len);
14 extern char *strcpy(char *dst, const char *src);
15 extern char *strncpy(char *dst, const char *src, size_t num);
16 extern char *strcat(char *dst, const char *src);
17 extern char *strdup(const char *src);
18 extern char *strndup(const char *src, int length);
19 extern char *strchr(const char *str, int character);
20 extern char *strrchr(const char *str, int character);
21 extern char *strstr(const char *str1, const char *str2);
24 extern void *memset(void *dest, int val, size_t count);
25 extern void *memcpy(void *dest, const void *src, size_t count);
26 extern void *memmove(void *dest, const void *src, size_t count);
27 extern int memcmp(const void *mem1, const void *mem2, size_t count);
28 extern void *memchr(const void *ptr, int value, size_t num);