We have learned lots of things in c programming, accept user input, execute, and print results on the terminal(output) window. But results are not store permanently, to store data for future reference we are using file handling in c language. Now, instead of accepting input and printing results from the terminal, we will use a file in c to accept input and store results. Accepting input from the file is called reading and printing output in a
What is a File?
The
- Text File: Text files are normal .txt files, that store information in ASCII format. The user can directly open that file and can read easily.
- Binary File: Binary files store information in the
binary format (0 or 1). Not user readable.
Basic File Operation in C Language.
When you are working with the file in c, you need to declare a pointer variable of FILE type to store file reference during reading or write operation. Below you can check basic file operation in c.
- Open or create a File.
- Read or Write a File.
- Close the File.
Example 1: C program to write user input in a File.
#include<stdio.h>
int main()
{
FILE *fp; //declaring a file pointer to store file reference.
char month[20];
fp=fopen("first.txt","w"); // opening a file in write mode.
printf("\nEnter Month: ");
scanf("%s",month);
fprintf(fp,"%s",month); //writing text in a file.
fclose(fp); //closinfg file.
return 0;
}FILE *fp – Here we are declaring a pointer variable of FILE type to store file reference in c programming.
fp=fopen(“first.txt”,”w”) – To open a file for read/write fopen(“file”,”mode”) function is used.
fprintf(fp,”%s”,weekday) – To write formated output in file, fprintf(file_pointer,”format”,text) function is used.
fclose(fp) – Every file must be close after read or write operation using fclose() function in c.
So, in the above c code first, we create a file pointer, open a file to write, after that write string into a
Example 2: C program to read text from a File.
#include<stdio.h>
int main()
{
FILE *fp; //declaring a file pointer to store file reference.
char month[20];
fp=fopen("first.txt","r"); // opening file in read mode.
fscanf(fp,"%s",month); //reading from file.
printf("\nMonth : %s",month);
fclose(fp); //closinfg file.
return 0;
}Mini Quiz
Mini Project
Mini Project: City Information
Question:
Write a C program that accepts the name of your favorite city from the user and stores it in a text file named city.txt. After storing the city name, read the data from the same file and display it on the screen.
View Answer Code
#include<stdio.h>
int main()
{
FILE *fp;
char city[30];
fp = fopen("city.txt", "w");
printf("Enter Your Favorite City: ");
scanf("%s", city);
fprintf(fp, "%s", city);
fclose(fp);
fp = fopen("city.txt", "r");
fscanf(fp, "%s", city);
printf("\nFavorite City: %s", city);
fclose(fp);
return 0;
}
Written by Shubhranshu Shekhar, who has trained 20000+ students in coding.
Shubhranshu Shekhar is a coding instructor, mentor, and founder of VSIT Delhi with 20+ years of teaching experience (since 2004). He has guided many students who are now working in multinational companies and specializes in Full Stack Development, Python, Digital Marketing, and Data Analytics.
