Search results: running the command in c
char * strncat (char * dest, const char * src, size_t n) append (string), pointed to by src, at the end of the string pointed to by dest, with a length of up to n characters.
strncpy char * (char * dest, const char * src, size_t n) copies up to n copies to n characters from the string pointed to by src to dest. in case the length of the src is smaller
the function size_t strcspn (const char * str1, const char * str2) calculates the length of the character segment of string str1 without containing the characters in str2.