库函数strncpy，字符数组与指针。还有字符数组结尾是'\0'

char *strncpy(char *s, char *ct, int n);

char *strncat(char *s, char *ct, int n);

int strncmp(char *cs, char *ct, int n);



char *strncpy(char *s, char *ct, int n) {

	char *sign = s;

	while(n-- > 0) 

		if(*s++ = *ct) ct++;

	return sign;

}



char *strncat(char *s, char *ct, int n) {

	char *sign = s;

	while(*s)

		s++;

	while(n-- && (*s++ = *ct++))

		;

	return sign;

}

#include<stdio.h>



#include "strncpy.c"



int getchar(void);



int main() {

	int i;

	char c[12] = "ca3456";

	char s[4] = "zsev";

	//char *z = c;

	strncat(c, s, 4);

	//if(*(s+3) == 'v')

		//printf("%c\n", *(s+4));

	for(i = 0; i < 12; i++)

		printf("%c\t\n", *(c+i));

	

	return 0;

}