Member Avatar for totalnoob

Hi! As you can see by my name I'm new to programming. I have a program that only works partially. It consists of two functions. One function creates a text file and reads it and the other one creates a binary file and reads it. The text file part works fine, but the binary part doesn't. It seems to create a file and write the contents but it doesn't read. So my question is why doesn't it read the contents of the file I created?
Thanks in advance!

#include <stdio.h>
#include <stdlib.h>

typedef struct
{   
  float re;  
  float im;  
}  complex ;


complex* entervalues( int amount ,complex*z);
void textfile(complex*,int amount);
void binaryfile(complex*,int amount);





int main(int argc, char *argv[])
{
   
    char answer1,choice;
    int m,i,amount;
  
complex *z,*z_array;
   
  printf("This program reads an arbitrary amount of complex numbers\n");
  printf("and stores them in a new file as either a text file or a binary file\n\n");
  printf("Do you wish to continue? (press 'y' to continue)");
  scanf("%c",&answer1);
  while(answer1=='y')
    {
    
 
       printf("How many complex numbers n will be written?");
      scanf("%d",&amount); 
    z_array= entervalues(amount,z); 
 
      printf(" \n\n   Textfile or binary file?\n");
      printf("To write to a text file please press t\n");
      printf("To write to a binary file please press b\n");
      printf("enter choice: ");
      fflush(stdin); scanf("%c",&choice);
     
     switch(choice)
      {
        case 't':
     textfile(z_array,amount);
       
         break;
   
         case 'b':
       binaryfile(z_array,amount);
 
 
           break; 
    } 
   
      
   
       printf("\n Again?\n");fflush(stdin);
       printf("Please enter answer(press 'y' to continue): ");scanf("%c",&answer1);
    }                    
  
   system("PAUSE");   
  return 0;
  free(z);free(z_array);
         }

complex* entervalues( int amount,complex* z)
    {
      z = (complex *) calloc(amount,sizeof(complex));
    printf("\n\n Please enter two values per number(z)\n ");
 
 
    int m;
     for (m=0; m<amount;m++)  
               {
     static int i=1;        
      
       printf("Please enter z%d: ",i++); //Here you write a complex number e.g. 1+2 
       scanf("%f %f",&(z+m)->re,&(z+m)->im); 
  
       
                 }
       return z;
            }



void textfile(complex*z_array, int amount)
              {
              FILE *textfile;
              char name[20],filename[20];
              float temp;
             
              printf("Please enter file name: ");
              scanf("%s",name);
           sprintf(filename,"%s", &name);
            
              textfile = fopen(filename, "w+");
            
            
           int k=0;
              for ( k=0;k<amount;k++)
               {
         fprintf(textfile, "%f %f ",(z_array+k)->re,(z_array+k)->im); 
    
               }
            
             rewind(textfile);
             printf("The numbers are: ");
        while (fscanf( textfile,"%f",&temp), !feof( textfile ))
            {
             fprintf( stdout," %.2f ",temp);
              }
              fclose( textfile );
                 return ;
                  }
                 
                 
                 
void binaryfile(complex*z_array ,int amount)                
                 {
               char filename[20];
               FILE *binaryfile;
               float temp;
               char name[20];
              
            printf("Please enter file name: "); 
              scanf("%s",filename);

             binaryfile = fopen( filename, "w+b");
          fwrite( z_array ,amount* sizeof( *z_array ) , 1 , binaryfile);//I think this part works. When i open the 
                                                                        // file with notepad I can see that the program   
                                                                        //has written something in jiberish, but I assume   
           rewind(binaryfile);                                          //that the numbers are right.      
             
            
             printf("The numbers are: ");
           
           

             while (!feof(binaryfile)) 
              {
              fread (&temp,amount*sizeof( *z_array  ), 1 ,binaryfile); //This part doesn't work! It only writes the 1st number
              printf(" %.2f ", temp ) ;                                //to the screen...
              }
              fclose( binaryfile );

              return ;

                }
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  • 8 Hours Discussion Span
  • Latest Post Latest Post by totalnoob
Member Avatar for Sci@phy

How do you expect it to work when you write "complex" into file, and try to get "float" out of it?

Member Avatar for Narue

>fread (&temp,amount*sizeof( *z_array ), 1 ,binaryfile);
temp is a float. Read your reference on fread again, double check the actual values you're passing it, and you'll see a problem.

Member Avatar for totalnoob

Thanks for your help!
It works! :icon_cheesygrin:

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