Запись, чтение, и редактирование данных в файле

#include <stdio.h>
#include <string.h>
#include <conio.h>
#include <windows.h>
void main()
{
    typedef struct
   {    char charvar[30];
       float floatvar;
        int intvar;
   } Info;
 Info data;
int i,n,newint,c,siz,m,z;
  int num;
char newch,newst[30],ch;
  FILE *myfile;
  FILE *myfile2;
menu:
clrscr();
printf("1 - Vvod\n");
printf("2 - Chtenie\n");
printf("3 - Dobavlenie\n");
printf("4 - Redaktirovanie\n");
printf("5 - Ydalenie\n");
ch=getch();
 
 
 switch (ch) {
 
 
 
 case 49: {
//====================ÓÓÐÐÐÀÀ!! Çàïèñü!============
myfile = fopen("D:/hardware.dat","wb");
printf("Vvod dannuh o tovarax:\n");
i=1;
 do
{ printf("\n N/N: %d\n",i);
  printf("\n  Nazvanie --> ");
 scanf("%s",&data.charvar);
 printf("\n  Stoumost' --> ");
 scanf("%f",&data.floatvar);
 printf("\n  Kolichestvo --> ");
 scanf("%d",&data.intvar);
 fwrite(&data,sizeof(Info),1,myfile);
 i++;
 printf("\nProdolzhit vvod tovarov?? Esc - net , Enter - da ");
 newch=getch();
 printf("\n");
} while (newch!=27);
fclose(myfile);goto menu; }  break;
 
 
 
//===================Äîáàâëåíèå ïîëó÷èëîñü ñ 1 ðàçà))======
case 51:{
 
  myfile = fopen("D:/hardware.dat","ab");
printf("Dobavlenie:\n");
 do
{printf("\n  Nazvanie --> ");
 gets(data.charvar);
 printf("\n  Stoumost' --> ");
 scanf("%f",&data.floatvar);
 printf("\n  Kolichestvo --> ");
 scanf("%d",&data.intvar);
 fwrite(&data,sizeof(Info),1,myfile);
 printf("\nProdolzhit vvod tovarov?? Esc - net , Enter - da ");
 newch=getch();
 printf("\n");
} while (newch!=27);
fclose(myfile);goto menu;
 }break;
 
 
 
case 50:{
//======================×òåíèå 2 ============
 printf("Vuvid dannuh o tovare:\n");
  myfile=fopen("D:/hardware.dat","rb"); //
i=1;
   fread(&data,sizeof(Info),1,myfile);
  do
 {
  printf("N\N: %d  |   Nazvanie: %s    Stoimost': %3.2f        Kolichestvo: %d \n",i,data.charvar,data.floatvar,data.intvar);
 fread(&data,sizeof(Info),1,myfile);
 i++;
 }
while (!feof(myfile));
fclose(myfile);
getch(); goto menu;}break;
 
//========================Ïîèñê==============================
case 52: {
printf("Edit:\n");
myfile=fopen("D:/hardware.dat","rb+"); // îòêðûòèå áèíàðíîãî ôàéëà äëÿ ÷òåíèÿ
printf("Nomer tovara -->");
scanf("%d",&siz);
i=1;
label1:
fread(&data,sizeof(Info),1,myfile);
if (siz==i)
{printf("\n N\N: %d \n\n",i); printf(" Nazvanie:"); puts(data.charvar);printf("\n");printf(" Stoimost': %3.2f\n\n Kolichestvo: %d \n\n",data.floatvar,data.intvar);
 
} else {
  i++; goto label1; } ;
printf("name ->"); scanf("%s",&data.charvar);
printf("cena ->"); scanf("%f",&data.floatvar);
printf("kol->");scanf("%d",&data.intvar);
fseek(myfile,-sizeof(Info),i);
 
fwrite(&data,sizeof(Info),1,myfile);
break;}
 
case 53:
{
clrscr();
  printf("Vuvod dannuh o tovare:\n");
  myfile=fopen("D:/ware.dat","rb");
   n=0;
  printf("\nBEFORE FREAD OF FILE: N=%d",n);
  fseek( myfile, 0, 2 );
  n = ftell(myfile) / sizeof(Info);
  printf("\nAFTER COUNTING OF FILE: N=%d",n);
  rewind(myfile);
 printf("\nNazvanue------>");
  scanf("%s",&newst);
  myfile2=fopen("D:/hardware1.dat","wb");
//i=1;
for(i=0;i<n-1;++i)
 { fread(&data,sizeof(Info),1,myfile);
 if(strcmp(newst,data.charvar)!=0)
fwrite(&data,sizeof(Info),1,myfile2) ;
// i++;
 }
 //while(!feof(myfile));
fclose(myfile);
fclose(myfile2);
printf("\n--->>%d",i);
 
 myfile2=fopen("D:/hardware1.dat","rb");
//i=1;
 myfile=fopen("D:/hardware.dat","wb");
 
 for(i=0;i<n-1;++i)
 
{
 fread(&data,sizeof(Info),1,myfile2);
fwrite(&data,sizeof(Info),1,myfile) ;
 
 }
 //while (!feof(myfile2));
 
 fclose(myfile);
fclose(myfile2);
//printf("\n--->>>%d",i);
 getch();
goto menu; }break;
 
 
}   }