IOday1

1.

  1 #include 
  2 #include 
  3 #include 
  4 int main(int argc, const char *argv[])
  5 {
  6     FILE *p1=fopen("1.txt","r");
  7     if(NULL==p1)
  8     {
  9         printf("__%d__",__LINE__);
 10         perror("fopen");
 11         return -1;
 12     }
 13     FILE *p2=fopen("2.txt","w");
 14     if(NULL==p2)
 15     {
 16         printf("__%d__",__LINE__);
 17         perror("fopen");
 18         return -1;
 19     }
 20 
 21 
 22     char c;
 23
 24     while(1)
 25     {
 26         c=fgetc(p1);
 27         if(EOF==c)
 28         {
 29             break;
 30         }
 31         fputc(c,p2);
 32     }                                                            
 33 
 34     if(fclose(p1)<0)
 35         return -1;
 36     if(fclose(p2)<0)
 37         return -1;
 38 
 39     return 0;
 40 }

 2,3.

  1 #include                                        
  2 #include 
  3 #include 
  4 int main(int argc, const char *argv[])
  5 {
  6     FILE *p=fopen("1.txt","r");
  7 
  8     FILE *p1=fopen("2.txt","r");
  9     int a=0,b=0;
 10 
 11     while(1)
 12     {
 13         if(fgetc(p)<0)
 14         {
 15             break;
 16         }
 17         a++;
 18     }
 19     printf("有%d个\n",a);
 20 
 21     int n;
 22     while((n=fgetc(p1))!=EOF)
 23     {
 24         if(n=='\n')
 25         b++;
 26 
 27     }
 28     printf("有%d行\n",b);
 29 
 30     if(fclose(p)<0)
 31     {
 32         return -1;
 33     }
 34     if(fclose(p1)<0)
 35     {
 36         return -1;
 37     }
 38 
 39 
 40     return 0;
 41 }

作业

 1.

  1 #include                                   
  2 #include 
  3 #include 
  4 int main(int argc, const char *argv[])
  5 {
  6     char name[20];
  7     char passwrod[20];
  8     printf("请输入账户:");
  9     scanf("%s",name);
 10     printf("请输入密码:");
 11     scanf("%s",passwrod);
 12 
 13     FILE *p=fopen("usr.txt","r");
 14     if(NULL==p)
 15     {
 16         perror("fopen");
 17         return -1;
 18     }
 19     char name1[20];
 20     char password1[20];
 21     int a,b,c1=0,c2=0;
 22     while(fscanf(p,"%s %s",name1,password1)!=EOF)
 23     {
 24         a=strcmp(name,name1);
 25         b=strcmp(passwrod,password1);
 26         if(a==0&&b==0)
 27         {
 28             c1++;
 29         }   
 30         if(a==0)
 31         {   
 32             c2++;
 33         }
 34     }
 35     if(c2)
 36     {
 37         if(c1)
 38         {
 39             printf("成功登录\n");
 40         }
 41         else
 42             printf("密码错误\n");
 43     }
 44     else
 45         printf("账户错误\n");
 46 
 47     fclose(p);
 48     return 0;
 49 }

 附加题

  1 #include 
  2 #include 
  3 #include 
  4 int main(int argc, const char *argv[])
  5 {
  6     char name[20];
  7     char passwrod[20];
  8     printf("请输入账户:");                                 
  9     scanf("%s",name);
 10     printf("请输入密码:");
 11     scanf("%s",passwrod);
 12 
 13     FILE *p=fopen("usr.txt","a+");
 14     if(NULL==p)
 15     {
 16         perror("fopen");
 17         return -1;
 18     }
 19     char name1[20];
 20     char password1[20];
 21     while(fscanf(p,"%s",name1)!=EOF)
 22     {
 23         if(strcmp(name,name1)==0)
 24         {
 25             printf("账户重复\n");
 26             return -1;
 27         }
 28     }
 29     fprintf(p,"%s %s",name,passwrod);
 30     printf("创建成功\n");
 31 
 32     fclose(p);
 33     return 0;
 34 }

 

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