C program to append content of one text file to another

Pre-requisite: File Handling in C
 

Given the source and destination text files, the task is to append the content from source file to destination file and then display the content of the destination file.
Examples: 
 

Input: 

file1.text
This is line one in file1
Hello World.
file2.text
This is line one in file2
Programming is fun.

Output: 
 
This is line one in file2
Programming is fun.
This is line one in file1
Hello World.

Approach: 

1. Open file1.txt and file2.txt with "a+"(append and read) option, so that the previous content of the file is not deleted. If files don't exist, they will be created.
2. Explicitly write a newline ("\n") to the destination file to enhance readability.
3. Write content from source file to destination file.
4. Display the contents in file2.txt to console (stdout). 
    

Output: 

Below is the output of the above program: 
 

👁 Image

 

Time Complexity: O(N) 
Auxiliary Space Complexity: O(1)