Question

I was trying to open a binary file in the directory and perform the operations accordingly.I doubt this line..is not the correct way of representation to work the below logic.

int main(int argc, char* argv[])
{
  int k=0;
  FILE *fp;
  unsigned char cd[255];
  unsigned long cd1[500];
  char *buffer;
  unsigned long sa=80044;
  int j=0,i=0,n=0;
  DIR *dir;
  struct dirent *direntry; //could be a file, or a directory

  dir = opendir("C:/Documents and Settings/Administrator/Desktop/vicky");
  if(!dir) {
  printf("Error: directory did not open!\n");
  return 1;
  }

  while((direntry=readdir(dir))!=NULL) {
  if(++k < 100)
  {
     printf("%s\n",direntry->d_name);
     sprintf(buffer,"%s",direntry->d_name);//here i got the unhanded exception.
     fp=fopen("buffer","rb");
     sa=sa-44;
     sa=sa/8;

  if(fp==NULL)
 {
   printf("file not found!");
 }
 else
      {
       for(j=0;j<(sa);j++)
       {
           for(i=0;i<8;i++)
           {
               cd[i]=fgetc(fp);//get each character from file 

              // printf("%c",cd[i]);

           }
           if(i==8)//if the i is 8 the character then do the following,just read 8 bytes  and then calculate the cd1.
           {
                sa=sa-8;
               cd1[j]=(cd[6] * 65536 + cd[5] * 256 + cd[4]);//multiply the positional weightage and calculate the cd1,which contains the 7 digits decimal value.

               //if((cd1[j]> 0x7FFFFF)&&(cd1[j]<=0xFFFFFF))

                 //cd1[j]=cd1[j]- 0xFFFFFF;
                 //cd1[j]=cd1[i] * -1;

           }
         printf("completes first 8 bytes read:%d - %d",j,cd1[j]);//print j and cd1[j] value in console window

       }
      fclose(fp);//close the file
   }


  }
  if((strcmp(direntry->d_name, "text.txt"))==0) {
     printf("\nThe %s file has been found\n",direntry->d_name);

     k=-99;  //just a flag value to show the file was found
     break;
   }

  }
  if(k!=-99)
  printf("\nThe test.txt file was not found\n");

  closedir(dir);

  printf("\n");
  getchar();
  return 0;

 }

This is error i got:Unhandled exception at 0x1029a189 (msvcr90d.dll) in READ_TEXT.exe: 0xC0000005: Access violation writing location 0xcccccccc.Kindly let me any suggestion to read the “direntry->d_name” file name to process the above logic.

Answer 1

Make the character buffer an ordinary array, for simplicity’s sake:

char buffer[1024];

That way you’re sure to have the memory put aside and ready to use. You should use snprintf() if your platform provides it.