C Program to Create a File and Write Data in it using fputs() and fputc() functions

C Program to Create a File and Write Data in it using fputs() and fputc() Functions

Introduction

This guide will demonstrate how to create a C program that effectively generates a new file and writes data into it. We’ll utilize two essential file I/O functions, fputs() and fputc(), to achieve this task, exploring their distinct capabilities and proper usage.

Key Concepts

• File Handling in C: C provides functions like fopen(), fputs(), fputc(), and fclose() to handle file operations.
• fputs() Function: Writes a string to a file, including the null terminator.
• fputc() Function: Writes a single character to a file.

Steps to Implement

1. Include Necessary Header:

C

#include <stdio.h>

2. Declare Variables:

C

FILE *fp;
char filename[50];
char data[100];
char ch;

3. Get File Name and Data from User:

C

printf("Enter the filename to create: ");
fgets(filename, sizeof(filename), stdin);
filename[strcspn(filename, "\n")] = '\0';  // Remove newline from filename

printf("Enter the data to write: ");
fgets(data, sizeof(data), stdin);

4. Open the File in Write Mode:

C

fp = fopen(filename, "w");

if (fp == NULL) {
    printf("Error creating file!\n");
    return 1;
}

5. Write Data Using fputs():

C

fputs(data, fp);

6. Write Additional Character Using fputc():

C

ch = '!';
fputc(ch, fp);  // Write a single character

7. Close the File:

C

fclose(fp);

8. Indicate Success:

C

printf("Data written to file successfully!\n");

Complete Example Code:

C

#include <stdio.h>

int main() {
    FILE *fp;
    char filename[50];
    char data[100];
    char ch;

    printf("Enter the filename to create: ");
    fgets(filename, sizeof(filename), stdin);
    filename[strcspn(filename, "\n")] = '\0';

    printf("Enter the data to write: ");
    fgets(data, sizeof(data), stdin);

    fp = fopen(filename, "w");

    if (fp == NULL) {
        printf("Error creating file!\n");
        return 1;
    }

    fputs(data, fp);

    ch = '!';
    fputc(ch, fp);

    fclose(fp);

    printf("Data written to file successfully!\n");

    return 0;
}

Key Points to Remember

• fputs() writes a string, including the null terminator, to the file.
• fputc() writes a single character to the file.
• Always check for file opening errors using if (fp == NULL).
• Close the file using fclose() when finished to release resources.
• Use "w" mode for writing to a new file or overwriting an existing one.
• Use "a" mode for appending to an existing file.