help withcreating sequential text file

[overlord21]

hi! i need rewrite this program using sequential text file!

 
#include<stdio.h>
#include<string.h>

typedef struct 
{  char last_name[15];
   char first_name[15];
   double grade_point_index;
}student;
typedef struct
{  char last_name[15];
   char first_name[15];
   double salary;
}employee;

int 
main(){
	int num_student;
	int num_employee;
	int i,k,j;
	student arr_student[5],temp;
	employee  arr_employee[5],temp1;
	printf("\nEnter the number of students==>  ");
	scanf("%d", &num_student);
	for(i=0;i<num_student;i++)
	{printf("\nEnter the last name of student %d==>",i+1 );
	scanf("%s",arr_student[i].last_name);
	printf("\nEnter the first name of student %d==>",i+1 );
	scanf("%s",arr_student[i].first_name);
	printf("\nEnter the grade point index of student %d==>",i+1 );
	scanf("%lf",&arr_student[i].grade_point_index);}
	
	
	for (k = 0; k <num_student; ++k)
		for (j = k+1; j <num_student; ++j){
			if (strcmp(arr_student[k].last_name,arr_student	[j].last_name)>0){
				temp=arr_student[k];
				arr_student[k]=arr_student[j];
				arr_student[j]=temp;}
			else if (strcmp(arr_student[k].last_name,arr_student[j].last_name)==0){
					if (strcmp(arr_student[k].first_name,arr_student[j].first_name)>0){
					temp=arr_student[k];
					arr_student[k]=arr_student[j];
					arr_student[j]=temp;}}
		}
	printf("Students' records \t last name \t first name \t grade point index  \n");
	for(i=0;i<num_student;i++)
	printf("                 \t %-8s    \t %-8s      \t %-8.2f \n",arr_student[i].last_name,arr_student[i].first_name,arr_student[i].grade_point_index);  


	printf("Enter the number of employees==>  ");
	scanf("%d", &num_employee);
	for(i=0;i<num_employee;i++)
	{printf("\nEnter the last name of employee %d==>",i+1 );
	scanf("%s",arr_employee[i].last_name);
	printf("\nEnter the first name of employee %d==>",i+1 );
	scanf("%s",arr_employee[i].first_name);
	printf("\nEnter the salary of employee %d==>",i+1 );
	scanf("%lf",&arr_employee[i].salary);
	}

	for (k = 0; k <num_employee; ++k)
		for (j = k+1; j <num_employee	; ++j){
			if (strcmp(arr_employee	[k].last_name,arr_employee[j].last_name)>0){
				temp1=arr_employee[k];
				arr_employee[k]=arr_employee[j];
				arr_employee[j]=temp1;}
			else if (strcmp(arr_employee[k].last_name,arr_employee[j].last_name)==0){
					if (strcmp(arr_employee	[k].first_name,arr_employee	[j].first_name)>0){
					temp1=arr_employee[k];
					arr_employee[k]=arr_employee[j];
					arr_employee[j]=temp1;}}
		}

	printf("\nThe Employees' records that you have entered are:  \n\n");
	printf("Employees' records \t last name \t first name \t salary  \n");
	for(i=0;i<num_employee;i++)
		printf("                 \t %-8s    \t %-8s      \t %-8.2f \n",arr_employee[i].last_name,arr_employee[i].first_name,arr_employee[i].salary);
for(i=0;i<num_student;i++)
	{for(j=0; j<num_employee; j++)
		if(strcmp(arr_employee[j].last_name,arr_student[i].last_name)==0 && strcmp(arr_employee[j].first_name,arr_student[i].first_name)==0)
			if(arr_student[i].grade_point_index>3)
				arr_employee[j].salary= arr_employee[j].salary * 1.10;}

printf("\n\nThe emplyees' salary after the increase: \n \n");
printf("Employees' records \t last name \t first name \t salary  \n");
	for(i=0;i<num_employee;i++)
		printf("                 \t %-8.3s    \t %-8s      \t %-8.3f \n",arr_employee[i].last_name,arr_employee[i].first_name,arr_employee[i].salary);
				
	return (0);
}

i need put data in an external files (ordered), one for students (called "students.dat"), one for employees (called "employees.dat").
2- read it in
3-change the salary of those employees who had a GPA greater than 3.0 as students
4- write out the changed employee array (the students' array doesn't change) to a file called "employees_updated.dat".

[tabstop]

And the problem is what? You know how to open and read a file, right?

[overlord21]

i'm a bit confused about the part"put data in an external files (ordered), one for students (called "students.dat"), one for employees (called "employees.dat"). and use of sequential text files (i don't see the difference comparing to random access files)

[tabstop]

Random access files must have records that are the same size, to allow you to access any record. Sequential files do not.

[overlord21]

so if i write something like this what is the problem?

#include<stdio.h>
#include<string.h>
typedef struct 
{  char last_name[15];
   char first_name[10];
   double grade_point_index;
}student;
typedef struct
{  char last_name[15];
   char first_name[15];
   double salary;
}employee;

int 
main(){
	FILE *cfPtr;
	int num_student;
	int num_employee;
	int i,k,j;
	student arr_student[5],temp;
	employee  arr_employee[5],temp1;
	
	if( ( cfPtr = fopen("file.dat", "wb+") ) == NULL )
		printf("couldn't open the file\a\a\a");
    else{	
	
	printf("\nEnter the number of students==>  ");
	scanf("&#37;d", &num_student);
	for(i=0;i<num_student;i++)
	{printf("\nEnter the last name of student %d==>",i+1 );
	scanf("%s",arr_student[i].last_name);
	printf("\nEnter the first name of student %d==>",i+1 );
	scanf("%s",arr_student[i].first_name);
	printf("\nEnter the grade point index of student %d==>",i+1 );
	scanf("%lf",&arr_student[i].grade_point_index);}
	
	
	for (k = 0; k <num_student; ++k)
		for (j = k+1; j <num_student; ++j){
			if (strcmp(arr_student[k].last_name,arr_student	[j].last_name)>0){
				temp=arr_student[k];
				arr_student[k]=arr_student[j];
				arr_student[j]=temp;}
			else if (strcmp(arr_student[k].last_name,arr_student[j].last_name)==0){
					if (strcmp(arr_student[k].first_name,arr_student[j].first_name)>0){
					temp=arr_student[k];
					arr_student[k]=arr_student[j];
					arr_student[j]=temp;}}
		}
	printf("Students' records \t last name \t first name \t grade point index  \n");
	for(i=0;i<num_student;i++)
	printf("                 \t %-8s    \t %-8s      \t %-8.2f \n",arr_student[i].last_name,arr_student[i].first_name,arr_student[i].grade_point_index);  
    }
    fclose(cfPtr);
}

[tabstop]

You're still prompting to the screen and waiting for input, rather than trying to use the file you opened? I don't know, why do you think there is a problem?

[overlord21]

well the file created is empty though

[tabstop]

You also write to the screen instead of writing to the file.

[overlord21]

!!! i don't know how to correct it ((fasting reduces cerebral activity)

[laserlight]

i don't know how to correct it

What is it?

fasting reduces cerebral activity

Stop fasting, or if this is due to Ramadan, then consider that professional programmers who are Muslim face the same problem but have to deal with it, and so do you.

[overlord21]

the problem ms laserlight is not about fasting its about how to make the program above print the outputs in the file

[tabstop]

So, did you bother to read the link I posted in my very first reply? If not, why not? If so, you wouldn't be asking the question.

[laserlight]

how to make the program above print the outputs in the file

Ah, so that is it, in which case the solution is to use fprintf() with your file handle, instead of just using printf().

[overlord21]

....one must be a master in programming to get answered here==(

[overlord21]

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