C Program To Merge Contents Of Two Files Into A Third File

C Program To Merge Contents Of Two Files Into A Third File

The given steps outline a simple process for merging the contents of two files, file1.txt and file2.txt, into a new file named file3.txt.

1. Open file1.txt and file2.txt in read mode.
2. Open file3.txt in write mode.
3. Copy characters from file1.txt to file3.txt in a loop.
4. Copy characters from file2.txt to file3.txt in a loop.
5. Close all files.

These steps describe a basic file merging operation where the contents of file1.txt and file2.txt are sequentially copied to a new file, file3.txt. This process can be implemented in various programming languages, such as C, C++, Python, etc.

Inorder to run the below program successfully, we have to include the file1.txt and fil2.txt must exits in the same folder

#include <stdio.h> 
#include <stdlib.h> 
  
int main() 
{ 
   // Open two files to be merged 
   FILE *fp1 = fopen("file1.txt", "r"); 
   FILE *fp2 = fopen("file2.txt", "r"); 
  
   // Open file to store the result 
   FILE *fp3 = fopen("file3.txt", "w"); 
   char c; 
  
   if (fp1 == NULL || fp2 == NULL || fp3 == NULL) 
   { 
         puts("Could not open files"); 
         exit(0); 
   } 
  
   // Copy contents of first file to file3.txt 
   while ((c = fgetc(fp1)) != EOF) 
      fputc(c, fp3); 
  // Copy contents of second file to file3.txt 
   while ((c = fgetc(fp2)) != EOF) 
      fputc(c, fp3); 
  
   printf("Merged file1.txt and file2.txt into file3.txt"); 
  
   fclose(fp1); 
   fclose(fp2); 
   fclose(fp3); 
   return 0; 
} 

Output

Merged file1.txt and file2.txt into file3.txt

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