3.21

#include <stdio.h>
#include <stdlib.h>


int main()
{
FILE * fp;
FILE * fp_w;
char ch;
if((fp = fopen("hello.txt","r+")) == NULL)
{
printf("cannot open\n");
exit(-1);
}


if((fp_w = fopen("hello_cp.txt","w+")) == NULL)
{
printf("cannot open\n");
exit(-1);
}


ch = fgetc(fp);
while(ch != EOF)
{
fputc(ch,fp_w);
ch = fgetc(fp);
}

//鏇村ソ鐨勫啓娉? // while((ch = fgetc(fp)) != EOF)
fclose(fp);
fclose(fp_w);
    return 0;
}