//WAP to input name, roll no, marks of n students and store them in file/ read from file also.
#include <stdio.h>
struct studentDetails{
char name[50];
int roll;
int marks;
}data[10];
int main(){
printf("Enter the name, roll no and marks of 10 students:\n");
for(int i=0; i<10; i++){
printf("Name: ");
scanf("%s",data[i].name);
printf("Roll: ");
scanf("%d",&data[i].roll);
printf("Marks: ");
scanf("%d",&data[i].marks);
}
FILE *fp = fopen("student_details.txt", "a");
for(int i=0; i<10; i++){
fprintf(fp, "%s\t%d\t%d\t\n", data[i].name, data[i].roll, data[i].marks);
}
printf("Entered Data: \nName\tRoll\tMarks\n");
fclose(fp);
fp = fopen("student_details.txt", "r");
char name[50];
int roll, marks;
while( fscanf(fp, "%s%d%d", name, &roll, &marks) != EOF ){
printf("%s\t%d\t%d\n", name, roll, marks);
}
fclose(fp);
return 0;
}This is a C program that allows the user to input the name, roll number, and marks of 10 students, and then stores the data in a file. The program also reads the data from the file and displays it on the console.
The program uses a structure studentDetails to define the attributes of each student - name, roll, and marks. An array of 10 studentDetails structures is declared using the variable data.
The main function prompts the user to input the data for 10 students using a for loop. The user is prompted to enter the name, roll number, and marks for each student, and the data is stored in the data array.
Then the program opens a file named "student_details.txt" in append mode using the fopen function. It writes the data of 10 students to the file using another for loop and fprintf function.
After writing the data to the file, the program prints the header for the data to be displayed. It then closes the file using the fclose function.
The program then opens the file again, this time in read mode, and reads the data from the file using a while loop and the fscanf function. The data is then displayed on the console using printf function.
Finally, the program closes the file using the fclose function and returns 0 to exit.
//WAP to rename and delete a file using rename and remove command.
#include <stdio.h>
int main(){
rename("data.txt", "new.txt");
printf("Renamed data.txt to new.txt\n");
remove("new.txt");
printf("Removed data.txt\n");
return 0;
}This is a C program that demonstrates how to rename and delete a file using the rename() and remove() functions.
The rename() function is used to change the name of a file from its original name to a new name. In this program, the function is used to rename the file "data.txt" to "new.txt". The syntax of the function is int rename(const char *oldname, const char *newname);, where oldname is the original name of the file, and newname is the new name of the file. The function returns 0 on success and a non-zero value on failure.
The remove() function is used to delete a file from the file system. In this program, the function is used to delete the file "new.txt". The syntax of the function is int remove(const char *filename);, where filename is the name of the file to be deleted. The function returns 0 on success and a non-zero value on failure.
When the program is executed, it renames the file "data.txt" to "new.txt" and prints the message "Renamed data.txt to new.txt". Then, it deletes the file "new.txt" and prints the message "Removed data.txt".
3. WAP to open a new file and read roll-no, name, address and phone number of students until the user says "no", after reading the data, write it to the file then display the content of the file.
//WAP to open a new file and read roll-no, name, address and phone number of students until the user says "no", after reading the data, write it to the file then display the content of the file.
#include <stdio.h>
int main(){
char name[50], address[100], ch;
int roll;
long int phone;
FILE *fp = fopen("data.txt", "a");
do{
printf("Enter name: ");
scanf("%s", name);
printf("Enter roll: ");
scanf("%d", &roll);
printf("Enter address: ");
scanf("%s", address);
printf("Enter phone: ");
scanf("%ld", &phone);
printf("\nDo you want to continue? [y/N]: ");
scanf(" %c", &ch);
fprintf(fp, "%s\t%d\t%s\t%ld\n", name, roll, address, phone);
}while(ch == 'y' || ch == 'Y');
fclose(fp);
fp = fopen("data.txt", "r");
printf("\n\nName\tRoll\tAddress\tPhone\n");
while(fscanf(fp, "%s%d%s%ld", name, &roll, address, &phone) != EOF){
printf("%s\t%d\t%s\t%ld\n", name, roll, address, phone);
}
return 0;
}This program allows the user to input information about students such as their name, roll number, address, and phone number. The information is read from the user until the user inputs "no". Then, the information is written to a file named "data.txt". After the information is written to the file, the content of the file is displayed.
The program starts by including the standard input/output library (stdio.h). The main function is defined, and four variables are declared - name, address, roll, and phone.
Then, a file pointer variable fp is created and is opened in "append" mode with the file name "data.txt". The user is prompted to enter the details of the student, and their input is read using scanf. Then, this data is written to the file using fprintf. The program checks whether the user wants to continue adding students by asking the user for input and storing the input in the variable "ch". This continues in a loop until the user inputs "no".
After the loop finishes, the file is closed using fclose. Then, the file is opened again, this time in "read" mode. The content of the file is read using fscanf in a loop until the end of the file is reached (indicated by EOF). The content is then printed to the console using printf.
Finally, the program ends by returning 0.
4. WAP to open a new file and store roll-no, name, address and phone number of specified number of students.
// writing details of students into a file using fwrite and fread for inbuilt to get formatted output
#include <stdio.h>
void students(int);
typedef struct Student {
char name[10];
int marks;
char phone[10];
int roll_num;
} Student;
int main() {
int len;
printf("Enter how many students are to be used:\n");
scanf("%d", &len);
students(len);
return 0;
}
void students(int len) {
Student std[len];
FILE *fp = fopen("students.dat", "w");
for (int i = 0; i < len; i++) {
printf("For student no [%d]\n", i + 1);
printf("enter name:");
scanf("%s", std[i].name);
printf("enter marks:");
scanf("%d", &std[i].marks);
printf("enter phone:");
scanf("%s", std[i].phone);
printf("enter roll_num:");
scanf("%d", &std[i].roll_num);
printf("-----------------------\n");
printf("-----------------------\n");
fwrite(&std[i], sizeof(Student), 1, fp);
}
fclose(fp);
printf("sucessfully wrote data into the file\n");
printf("-----------------------\n");
printf("-----------------------\n");
// to read from a file
fp = fopen("students.dat", "r");
for (int i = 0; i < len; i++) {
fread(&std[i], sizeof(Student), 1, fp);
printf("Name:%s\n", std[i].name);
printf("Phone:%s\n", std[i].phone);
printf("Marks:%d\n", std[i].marks);
printf("Roll:%d\n", std[i].roll_num);
printf("---------------------------\n");
}
}This program asks the user for the number of students whose details should be entered.
fwrite, fread funtions are used because it will auto format the details when writing to a file.
A quick runthrough of the program.
- asks for number of students
- asks for details of the students
- writes the details of the student in the file
- opens the file and prints out it's content
Released under MIT by @ComputeNepal.
