程序代码：

#include<stdio.h>
#include<stdlib.h>
#define LEN 81
int main(int argc,char*argv[])
{
    FILE*fp,*target;
    char ch;
    if(argc!=3)
    {
        printf("123\n");
        exit(1);
    }
    if((fp=fopen(argv[1],"r"))==NULL||(target=fopen(argv[2],"w"))==NULL)
    {
        printf("Can not open\n");
        exit(1);
    }
    while((ch=getc(fp))!=EOF)
        putc(ch,target);
    while((ch=getc(target))!=EOF)
        putc(ch,stdout);
    return 0;
}应该把这代码怎样改