Answer to Question #207201 in C for Ali khan

Question

Write a program which writes student name, registration number, semester, section 

and CGPA of a student in a file entitled “student.dat” using structure. Repeat file 

writing for as much number of students as user want.

Answer 1

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


struct student{
	char name[30];
	char registrationNumber[30];
	int semester;
	char section[30];
	float CGPA;
};


void saveStudentsToFile(struct student students[],int totalStudents);
//The start point of the program
int main( void){
	struct student students[100];
	int totalStudents=0;
	int totalTestPercentages=0;
	int exit=1;


	 FILE *infile; 
    struct student input; 
      
    // Open students.dat for reading 
    infile = fopen ("students.dat", "r"); 
	if (infile != NULL)
    {
		printf ("%-20s%-20s%-20s%-20s%-20s\n", "Name", "Reg. Number","Semester","Section", "CGPA"); 
       // read file contents till end of file 
		while(fread(&input, sizeof(struct student), 1, infile)){
			printf ("%-20s%-20s%-20d%-20s%-20.1f\n", input.name, input.registrationNumber, input.semester, input.section, input.CGPA); 
		}
		// close file 
		fclose (infile); 
    }
    
	while(exit==1){
		printf("Enter a student name: ");
		gets(students[totalStudents].name);
		printf("Enter a student registration number: ");
		gets(students[totalStudents].registrationNumber);
		printf("Enter a student semester: ");
		scanf("%d",&students[totalStudents].semester);
		fflush(stdin);
		printf("Enter a student section: ");
		gets(students[totalStudents].section);
		printf("Enter a student CGPA: ");
		scanf("%f",&students[totalStudents].CGPA);
		totalStudents++;
		printf("Do you want to add a new student? 1 - yes, 0 - no: ");
		scanf("%d",&exit);
		fflush(stdin);
	}


	saveStudentsToFile(students,totalStudents);


	getchar();
	getchar();
	return 0;
}


void saveStudentsToFile(struct student students[],int totalStudents){
	FILE *outStudentsFile;
	int i=0;
	// open file for writing
	outStudentsFile = fopen ("students.dat", "w");


	// write struct to file
	for(i=0;i<totalStudents;i++){
		fwrite (&students[i], sizeof(struct student),1, outStudentsFile);
	}
	// close file
	fclose (outStudentsFile);
}