- C++ Programming Examples
- C++ Programming Examples
- C++: Hello World
- C++: Get Input
- C++: Print Integer
- C++: Add two numbers
- C++: Add, Sub, Multiply, Div
- C++: Add Digits
- C++: Find Average and Percentage
- C++: Find Arithmetic Mean
- C++: Sum of n Natural Numbers
- C++: Sum of n Numbers
- C++: Square's Area and Perimeter
- C++: Rectangle's Area and Perimeter
- C++: Triangle's Area and Perimeter
- C++: Area and Circumference
- C++: Find Simple Interest
- C++: Fahrenheit to Celsius
- C++: Celsius to Fahrenheit
- C++: Print Prime Numbers
- C++: Reverse a Number
- C++: Swap Two Numbers
- C++: Print Multiplication Table
- C++: Find Factorial of a Number
- C++: Find Factors of a Number
- C++: Find HCF and LCM
- C++: Create a Calculator
- C++: Count Digits in a Number
- C++: First and Last Digit Sum
- C++: Product of Number Digits
- C++: Sum of Squares of Digits
- C++: Interchange Digits of Number
- C++ if-else Programs
- C++: Check Even or Odd
- C++: Check Prime or Not
- C++: Check Alphabet or Not
- C++: Check Vowel or Not
- C++: Check Leap Year or Not
- C++: Check Reverse equals Original
- C++: Check Perfect Number
- C++: Check Palindrome or Not
- C++: Check Armstrong or Not
- C++: Divisibility Test
- C++: Find Labor Wage
- C++: Find Discounted Price
- C++: Find Shipping Charge
- C++: Find Telephone Bills
- C++: Calculate Student Grade
- C++: Largest of Two Numbers
- C++: Largest of Three Numbers
- C++ Number Conversion
- C++: Decimal to Binary
- C++: Decimal to Octal
- C++: Decimal to Hexadecimal
- C++: Binary to Decimal
- C++: Binary to Octal
- C++: Binary to Hexadecimal
- C++: Octal to Decimal
- C++: Octal to Binary
- C++: Octal to Hexadecimal
- C++: Hexadecimal to Decimal
- C++: Hexadecimal to Binary
- C++: Hexadecimal to Octal
- C++ Pattern Programs
- C++: Pattern Programs
- C++: Print Diamond Pattern
- C++: Print Floyd's Triangle
- C++: Print Pascal's Triangle
- C++ Array Programs
- C++: 1D Array Program
- C++: Linear Search
- C++: Binary Search
- C++: Largest Element in an Array
- C++: Smallest Element in an Array
- C++: Find Second Largest Element
- C++: Find Second Smallest Element
- C++: Sum of All Elements
- C++: Multiply All Elements
- C++: Element in Even Position
- C++: Element in Odd Position
- C++: Print Even Numbers in Array
- C++: Print Odd Numbers in Array
- C++: Count Even or Odd Numbers
- C++: Sum of Even or Odd Numbers
- C++: Count Positive, Negative, Zero
- C++: Reverse an Array
- C++: Insert an Element
- C++: Delete an Element
- C++: Merge two Arrays
- C++: Bubble Sort
- C++: Selection Sort
- C++: Insertion Sort
- C++: Common Elements
- C++: 2D Array Programs
- C++: Add Two Matrices
- C++: Subtract Two Matrices
- C++: Transpose Matrix
- C++: Multiply Two Matrices
- C++: 3D Array Programs
- C++ String Programs
- C++: Print String
- C++: Find String Length
- C++: Compare Two Strings
- C++: Copy String
- C++: String Concatenation
- C++: Reverse a String
- C++: Delete Vowels from a String
- C++: Delete a Word from a String
- C++: Count Characters in a String
- C++: Count Words in a String
- C++: Frequency of Words
- C++: Remove Spaces from Strings
- C++: Sort a String
- C++: Uppercase to Lowercase
- C++: Lowercase to Uppercase
- C++: Swap Two Strings
- C++: Check the Anagram or Not
- C++: Capitalize All Words in a String
- C++: Get Numbers from a String
- C++ File Programs
- C++: Read a File
- C++: Write Content to a File
- C++: Append Data to a File
- C++: Read and Display File
- C++: Copy a File
- C++: Merge Two Files
- Count Characters in a File
- C++: Capitalize Every Word
- C++: List Files in Directory
- C++: Delete a File
- C++: Encrypt and Decrypt a File
- C++ Misc Programs
- C++: Print ASCII Value
- C++: Add Binary Numbers
- C++: Generate Random Numbers
- C++: Print a Smiling Face
- C++: Days into Years and Months
- C++: Add Two Numbers using Pointer
- C++: Print Fibonacci Series
- C++: Generate Armstrong Numbers
- C++: Find nCr and nPr
- C++: Get IP Address
- C++: Print Date and Time
- C++: Shutdown and Restart Computer
- C++ Programming Tutorial
- C++ Tutorial
C++ Program to Append Data in a File
This article is created to provide you with the program in C++ that appends some data to a file. Here, both data and files must be entered by the user at run-time. Adding new data to a file without erasing the previous one is referred to as appending data.
What Should You Do Before the Program?
A file is required to append some data inside the file. Therefore, I've created a file inside the current directory (the folder where my C++ source code is saved or going to be saved). Here is the snapshot of the current directory where the file was created:
The file named fresherearth.txt is available, as shown in the above screenshot.That is created by me right now. Let's put some content inside it. Here is a snapshot of the opened file after writing some data manually inside it:
since I've got a file with some data already available in it. Therefore, now let's move on and create a program in C++ that appends some new data entered by the user at run-time to this file using a C++ program.
Append Data in a File
The question is: write a C++ program that receives the name of a file and data and appends the given data inside the given file. The answer to this question is the program given below:
#include<iostream> #include<fstream> #include<string.h> using namespace std; int main() { char filename[20], str[500]; fstream fp; cout<<"Enter File's Name: "; gets(filename); fp.open(filename, fstream::app); if(!fp) { cout<<"\nFile doesn't exist or Access denied!"; return 0; } cout<<"Enter the Data: "; gets(str); while(strlen(str)>0) { fp<<"\n"; fp<<str; gets(str); } fp.close(); cout<<endl; return 0; }
The snapshot given below shows the initial output produced by the above C++ program on appending data to a file:
Now provide the name of the file that was created earlier, which is fresherearth.txt, and then enter some data, saying:
The first text gets append
That is, type The first, then press the ENTER key, then type text to and press the ENTER key again, and finally type append and hit the ENTER key two times to stop entering further data and append the complete data entered in the file fresherearth.txt, as shown in the snapshot given below. Here is its sample run with exactly the same inputs:
Now if you see the same file, fresherearth.txt, then you'll find that the above-entered texts and data get appended. Here is the new snapshot of the opened file:
Note: The fstream header file is included to use its class fstream to handle the file stream.
Note: The fstream is a stream class used for both read and write purposes.
Note: The fstream::app is used to open the file in appending mode.
But the above program does not provide a good user experience. I mean, the user doesn't see the on-going process of the above program. Even they are not able to see whether the data entered by him or her gets appended or not. Therefore, I've created another program that gives a good user experience:
#include<iostream> #include<fstream> #include<string.h> using namespace std; int main() { char filename[20], str[500], ch; fstream fp; cout<<"Enter File's Name: "; gets(filename); fp.open(filename, fstream::app); if(!fp) { cout<<"\nFile doesn't exist or Access denied!"; return 0; } else cout<<"\nThe file is available in the directory"; cout<<"\nEnter the Data: "; gets(str); while(strlen(str)>0) { fp<<"\n"; fp<<str; gets(str); } cout<<"\nEntered data appended to the file successfully!"; fp.close(); cout<<"\nWant to see the content of file ? (y/n) "; cin>>ch; if(ch=='y') { fstream fp; fp.open(filename, fstream::in); cout<<"-----"<<filename<<"--------\n"; while(fp>>noskipws>>ch) cout<<ch; fp.close(); } cout<<endl; return 0; }
Here is its sample run with user inputs, fresherearth.txt as the name of the file, and:
The second text to append.
as data to append, and y as a choice:
And here is the new snapshot of the opened file, fresherearth.txt:
As you can see from the above program and its sample run, the user is able to see the on-going process as well as the content of the file (if he or she wants) after appending new data to the file. That is, basically, the user does not need to go inside the directory and open the file manually to see its new content after appending, as this is done using the program itself.
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