这样也可以~  
   /*while(!feof(in))
     {
            len++;
            ch = fgetc(in);
     }*/

     fseek(in,0L,2);
     len=ftell(in);
     fseek(in, 0L,0);

输出在屏幕上的字符不全

好，谢谢

输出在屏幕的字符不全

怎么处理输出在屏幕的字符不全

 #include<stdio.h>
  #include<windows.h>
  #include<stdlib.h>
  main()
  {
        char start[100];
      int len = 0 ,t = 0 ,l = 0;
      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);
      }
      
      fseek(in,0L,2);
      len=ftell(in);
      fseek(in, 0L,0);
      
      while(!feof(in))
      {
          t++;
          ch=fgetc(in);
          fputc(ch,out);
          start[t-1] = ch;
          printf("%*.*s",-(len+1),t,start);
          
          printf("\t\t");
          printf("%.2lf", 1.0*(t-1)/len);
          Sleep(280);
          for(l = 0; l <+12+len+1+3; l++)
          {
              printf("\b");
          }
          
      }
      putchar(10);
      fclose(in);
      fclose(out);
  }

给你一段能运行的代码  

#include <stdio.h>
#include <string.h>
#include <windows.h>

int main(void)
{
    FILE *in,*out;
    char ch;
    in=fopen("1.txt","rb");
    out=fopen("2.txt","w");
    fseek(in,0,SEEK_END);
    int fsize=ftell(in);
    char* t="Now it will copping completed: ";
    int len=(int)strlen(t);
    fseek(in,0,SEEK_SET);
    ch=fgetc(in);
    int i=1;
    while(!feof(in))
    {
        fputc(ch,out);
        printf("%s %6.2lf",t,1.0*i/fsize*100);
        Sleep(30);
        for(int k=0;k<len+7;k++) printf("\b");
        ch=fgetc(in);
        i++;
    }
    printf("\n");
    fclose(in);
    fclose(out);
    return 0;
}

不过这么做代价有些大   原本不到一秒就可以完成的copy动作  变成好几十倍了

主要是你还没明白在控制台下显示进度表 是什么原理  、
出现吃字符的现象  主要是清屏不给力 没有完整的清屏