#ifndef _C_STRING_H #define _C_STRING_H #include #ifdef __cplusplus extern "C" { #endif size_t strlen(const char *str); char *strcpy(char *dest, const char *src); char *strncpy(char *dest, const char *src, size_t num); int strcmp(char *str1, char *str2); int strncmp(char *str1, char *str2, size_t num); #ifdef __cplusplus } #endif #endif