//********************************************
//文件名：COMPSF.C
//功能：比較兩個扇區文件，報告不相同的字節編號
//********************************************
#include<stdio.h>                         //1.
#include<stdlib.h>                        //2.
void main()                               //3.
{                                         //4.
  FILE *fp1,*fp2,*fp3;                    //5.
  long i=1,j=0;                           //6.
  char c1[13],c2[13];                     //7.
  char ch1,ch2;                           //8.
  printf("Filename1: ");                  //9.
  scanf("%s",c1);                         //10.
  printf("Filename2: ");                  //11.
  scanf("%s",c2);                         //12.
  if((fp1=fopen(c1,"rb"))==NULL)          //13.
  {                                       //14.
    printf("File1 not found!\n");         //15.
    exit(0);                              //16.
  }                                       //17.
  if((fp2=fopen(c2,"rb"))==NULL)          //18.
  {                                       //19.
    printf("File2 not found!\n");         //20.
    exit(0);                              //21.
  }                                       //22.
  fp3=fopen("compsf.txt","wb");           //23.打開寫入數據的文件
  fprintf(fp3,"Different bytes:\n");      //24.
  while(!feof(fp1))                       //25.測試文件是否到尾
  {                                       //26.
    ch1=fgetc(fp1);                       //27.
    ch2=fgetc(fp2);                       //28.
    if(ch1!=ch2)                          //29.若兩字符不相同
    {                                     //30.
      fprintf(fp3,"%ld\n",i);             //31.將字節編號寫入文件
      j++;                                //32.
    }                                     //33.
    i++;                                  //34.
  }                                       //35.
  fprintf(fp3,"Ok!\n");                   //36.
  fclose(fp1);                            //37.
  fclose(fp2);                            //38.
  fclose(fp3);                            //39.
  if(j==0)                                //40.若無不相同的字節
  {                                       //41.
    printf("Ok! no differences "          //42.
    "encountered.\n");                    //43.
    remove("compsf.txt");                 //44.刪除文件
  }                                       //45.
  else                                    //46.
    printf("Differences: %ld bytes\n",j); //47.顯示不相同的字節總數
}                                         //48.