c语言字符串学习

#include <stdio.h>

int main(int argc, char *argv[])
{
char str[]="hello world!";
char str1[]={'h','e','l','l','o',' ','w','o','r','l','d','!','\0'};
//这两句是等价的

FILE *p;
char *filename="c:\\2.txt";

printf("%d\n",strlen(str));
printf("%d",strlen(str1));


if(p=fopen(filename,"r") !=NULL){
    printf("%d",p);
    puts("char");
}
    return 0;
}