Please note, this is a STATIC archive of website www.w3resource.com from 19 Jul 2022, cach3.com does not collect or store any user information, there is no "phishing" involved.
w3resource

C Exercises: Merge two files and write it in a new file

C File Handling : Exercise-12 with Solution

Write a program in C to merge two files and write it in a new file.

Assume that the content of the file test.txt and test1.txr is :                                                                       
 The content of the file test.txt is  : 
This is the file test.txt. 

 The content of the file test1.txt is  : 
This is the file test1.txt.                                                                                                    

Sample Solution:

C Code:

#include <stdio.h>
#include <stdlib.h>

void main()
{
	FILE *fold1, *fold2, *fnew;
	char ch, fname1[20], fname2[20], fname3[30];

	printf("\n\n Merge two files and write it in a new file :\n");
	printf("-------------------------------------------------\n"); 	
	
	printf(" Input the 1st file name : ");
	scanf("%s",fname1);
	printf(" Input the 2nd file name : ");
	scanf("%s",fname2);
	printf(" Input the new file name where to merge the above two files : ");
	scanf("%s",fname3);
	fold1=fopen(fname1, "r");
	fold2=fopen(fname2, "r");
	if(fold1==NULL || fold2==NULL)
	{
//		perror("Error Message ");
		printf(" File does not exist or error in opening...!!\n");
		exit(EXIT_FAILURE);
	}
	fnew=fopen(fname3, "w");
	if(fnew==NULL)
	{
//		perror("Error Message ");
		printf(" File does not exist or error in opening...!!\n");
		exit(EXIT_FAILURE);
	}
	while((ch=fgetc(fold1))!=EOF)
	{
		fputc(ch, fnew);
	}
	while((ch=fgetc(fold2))!=EOF)
	{
		fputc(ch, fnew);
	}
	printf(" The two files merged into %s file successfully..!!\n\n", fname3);
	fclose(fold1);
	fclose(fold2);
	fclose(fnew);
}

Sample Output:

 Merge two files and write it in a new file :                                                                 
-------------------------------------------------                                                             
 Input the 1st file name : test.txt                                                                           
 Input the 2nd file name : test1.txt                                                                          
 Input the new file name where to merge the above two files : mergefiles.txt                                  
 The two files merged into mergefiles.txt file successfully..!!

Flowchart:

Flowchart: Merge two files and write it in a new file

C Programming Code Editor:

Have another way to solve this solution? Contribute your code (and comments) through Disqus.

Previous: Write a program in C to copy a file in another name.
Next: Write a program in C to encrypt a text file.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



C Programming: Tips of the Day

Static variable inside of a function in C

The scope of variable is where the variable name can be seen. Here, x is visible only inside function foo().

The lifetime of a variable is the period over which it exists. If x were defined without the keyword static, the lifetime would be from the entry into foo() to the return from foo(); so it would be re-initialized to 5 on every call.

The keyword static acts to extend the lifetime of a variable to the lifetime of the programme; e.g. initialization occurs once and once only and then the variable retains its value - whatever it has come to be - over all future calls to foo().

Ref : https://bit.ly/3fOq7XP