#include<stdio.h>
#include<stdlib.h>
int main()
{
    char file[10],file1[10],ch;
    FILE *in,*out;
    scanf("%s",file);
    scanf("%s",file1);
    if((in=fopen(file,"r"))==NULL)
    {
        printf("can't open file\n");
        exit(0);
    }
    if((out=fopen(file1,"w"))==NULL)
    {
        printf("can't open file1\n");
        exit(0);
    }
    while(!feof(in))
    {
        ch=fgetc(in);
        fputc(ch,out);
        putchar(ch);
    }
    fclose(in);
    fclose(out);
    return 0;
}
我事先创建了一个文本文件work.txt，把里面的内容要复制的到另一个文件work1中，用上述代码输入
work.txt
work1
可以得到输出
可是把打开文件的语句改成下面的样子之后就无法编译通过，这是为什么
#include<stdio.h>
#include<stdlib.h>
int main()
{
    char file[10],file1[10],ch;
    FILE *in,*out;
//    scanf("%s",file);
//    scanf("%s",file1);
//    if((in=fopen(file,"r"))==NULL)
改后的  if((in=fopen(work.txt,"r"))==NULL)
    {
        printf("can't open file\n");
        exit(0);
    }
//    if((out=fopen(file1,"w"))==NULL)
改后的  if((out=fopen(work1,"w"))==NULL)
    {
        printf("can't open file1\n");
        exit(0);
    }
    while(!feof(in))
    {
        ch=fgetc(in);
        fputc(ch,out);
        putchar(ch);
    }
    fclose(in);
    fclose(out);
    return 0;
}