Thread: help withcreating sequential text file

where should i insert it

exuse for lack of understanding

i'll just let it for now it just that the instructor did only the lectur with no exemple of an implementation using fprintf and stuff. I'll make my mind later

http://www.cppreference.com/wiki/c/io/fopen
http://www.cppreference.com/wiki/c/io/fprintf
http://www.cppreference.com/wiki/c/io/fclose

thanks for the useful links. So the result that i got is this

Code:

#include<stdio.h>
#include<string.h>
#define size 5           


typedef struct {
	char last[10];                        /* Structure of type student*/
	char first[10];              
    double gpa;
} stud;


typedef struct {
	char last[10];
	char first[10];                      /* structure of type employee*/
	double salary;
}  emp;


void check_add_salary (emp *e, stud *s);




main(){ 

FILE *stud_file=NULL;
FILE *employ_file=NULL;
FILE *employ_file2=NULL;
int i=0 , j=0;
stud arr_stud[size];                                                  /* An array of structures (students)*/
emp arr_emp[size];                                                    /*An array of structures (employees)*/
                

if((stud_file=fopen("student.txt","r"))==NULL) 
   printf("\nThe file could not be opened\n\n");

else
   {   fseek(stud_file,50,SEEK_SET);
       while(!feof(stud_file))
   	   {fscanf(stud_file,"&#37;s%s%lf\n", arr_stud[i].last,arr_stud[i].first,&arr_stud[i].gpa);
   
       i++;
   	   }
   
       
       
     
     
      fclose(stud_file);
   }
   /*end of else*/
   
   i=0;
   
   if((employ_file=fopen("employees.txt","r"))==NULL)
{  
   printf("\nThe file could not be opened\n\n");
}

else 
   {
     fseek(employ_file,51,SEEK_SET);
   	 while(!feof(stud_file))
	   	{
   	    fscanf(employ_file,"%s%s%lf\n", arr_emp[i].last,arr_emp[i].first,&arr_emp[i].salary);
 	   
        i++;   
        }
   
   fclose(employ_file);
   
   
   
   
   }
   
   /***end of reading from file employess*/
   
   
   check_salary(arr_emp,arr_stud);
   
   
   
   if((employ_file2=fopen("update.txt","w"))==NULL)
{  
   printf("\nThe file could not be opened\n\n");
}

else 
   {  fputs("\t\tThe new list of employees(after salary change)\n\n",employ_file2);
       fputs("Last name\tFirst name\t\tGPA\n",employ_file2);
       fputs("************************************************\n",employ_file2);
       
       for(i=0;i<size;i++)
         fprintf(employ_file2,"%-10s      %-10s               %-10.2f\n", arr_emp[i].last,arr_emp[i].first,arr_emp[i].salary);   /* Display the list of employees sorted by alphabetical order*/
	   
       fputs("\n************************************************\n\n\n\n",employ_file2);
       fclose(employ_file2);
   
   
   
  
  printf("\n The file of employees with the new salary has been created n\" );
   


   
}
   void check_salary (emp *r, stud *s)
   	{
   	
   		int i , j;
        for(i=0;i<size;i++)
          for(j=0;j<size;j++)
            if( strcmp (e[i].last,s[j].last)==0 && strcmp(e[i].first,s[j].first)==0 )
              if(s[i].gpa>3.0)                                                                                             /* The if statement is to add 10% to the salary*/
                {																														/*of employees whose students have GPA>3*/
		        	r[i].salary = r[i].salary + ((r[i].salary)*0.1); j=size-1;
		     	}       
			
   }

but by using fseek its no more sequential . Anyone can tell how to make sequential?

Thanks

Originally Posted by overlord21

thanks for the useful links. So the result that i got is this but by using fseek its no more sequential . Anyone can tell how to make sequential?

Thanks

Don't use fseek? It would seem to be wrong in this context.

i see so the program is fine as it is now right ot should i remove one fseek since i use two?...... and for the " printf("\n The file of employees with the new salary has been created\n\n\");" it tells me that there is some unterminated string or character ..

Originally Posted by C_ntua

EDIT: I believe the difference with sequential and random access lies on the hardware, not the software. If you had a tape you will have to read from the beginning to the end. In a HD you can read from wherever you want. If you kind of think though how a tape reader would work, it would be fine to use fseek() if the tape reader wasn't too simple. If the tape reader didn't want to use the same functions with files then it would have its own, thus no fseek(). Anyway. Sequential is really not going back to the file. Thus not using fseek() to go back. But in any case, yeah, just not use fseek

wow with this i'm more confused,ok then if i don't use fseek and want to skip reading the first line of the line how should i do it?

Originally Posted by overlord21

aie! it tells errors as i change printf(too few arguments)

Code:

Example:
#include <stdio.h>

int main(void)
{
   FILE *stream;
   int i = 100;
   char c = 'C';
   float f = 1.234;

   /* open a file for update */
   stream = fopen("DUMMY.FIL", "w+");

   /* write some data to the file */
   fprintf(stream, "%d %c %f", i, c, f);

   /* close the file */
   fclose(stream);
   return 0;
}

A simple example.

thanks and for the little problem in my last post can you help? Adak?

well i removed the fseek and it works