#include<stdio.h>
#include<stdlib.h>
void main()
{
    FILE *in,*out;
    char ch,infile[10],outfile[10];
    printf("enter the name of the fileread:");
    scanf("%s",infile);
    printf("enter the name of the filewrite:");
    scanf("%s",outfile);
    if(in=fopen(infile,"r")==NULL)
    {
        printf("can not open the file!\n");
        exit(0);
    }
    if(out=fopen(outfile,"w")==NULL)
    {
        printf("can not open the file!\n");
        exit(0);
    }
    while(!feof(in))
    {
        ch=fgetc(in);
        fputc(ch,out);
        putchar(ch);
    }
    putchar(10);
    fclose(in);
    fclose(out);
}

你敢再说的详细一些吗

就是C语言关于读取文件的问题

你想干啥（期望值） 而实际结果是？

就是读取一个文件，然后读取它的内容并将内容写入另一个文件

#include<stdio.h>
#include<stdlib.h>
void main()
{
    FILE *in,*out;
    char ch,infile[10],outfile[10];
    printf("enter the name of the fileread:");
    scanf("%s",infile);
    printf("enter the name of the filewrite:");
    scanf("%s",outfile);
    if(in==fopen(infile,"r")==NULL)
    {
        printf("can not open the file!\n");
        exit(0);
    }
    if(out==fopen(outfile,"w")==NULL)
    {
        printf("can not open the file!\n");
        exit(0);
    }
    while(!feof(in))
    {
        ch=fgetc(in);
        fputc(ch,out);
        putchar(ch);
    }
    putchar(10);
    fclose(in);
    fclose(out);
}

= 是赋值，= =这是判断相等

还是不对啊，我是用out和in这两个指针变量指文件里面的内容

     if((in =fopen(infile,"r"))==NULL)      //加小括号
     {
         printf("can not open the file!\n");
         exit(0);
     }
     if((out=fopen(outfile,"w"))==NULL)     //加小括号
     {
         printf("can not open the file!\n");
         exit(0);
     }

给你一个能运行的代码吧（精简之后的，你的原码逻辑有问题 复制后文件与原始文件会有一个byte的差异）

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

void main()
{
    FILE *in,*out;
    char ch;
    in=fopen("1.txt","r");
    out=fopen("2.txt","w");
    ch=fgetc(in);
    while(!feof(in))
    {
        fputc(ch,out);
        ch=fgetc(in);
    }
    fclose(in);
    fclose(out);
}