- C Programming Examples
- C Programming Examples
- C Print Hello World
- C Get Input from User
- C Print Integer
- C Add Two Numbers
- C Add Subtract Multiply Divide
- C Add n Numbers
- C Area Perimeter of Square
- C Area Perimeter of Rectangle
- C Area Circum of Circle
- C Fahrenheit to Celsius
- C Celsius to Fahrenheit
- C Inches to Centimeters
- C Kilogram to Gram
- C Reverse a Number
- C Swap Two Numbers
- C Interchange Numbers
- C Print ASCII Value
- C Print Fibonacci Series
- C Check Palindrome or Not
- C Check Armstrong or Not
- C Find Armstrong Numbers
- C Find nCr and nPr
- C Find Profit Loss
- C Sum of their Square
- C First & Last Digit Sum
- C Sum of All Digit
- C Product of All Digit
- C Print Total Digit in Number
- C Check Perfect Number
- C Find Basic Gross Salary
- C Round Number to Integer
- C Print Series upto n Term
- C Find Factors of Number
- C if-else & Loop 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 Is Reverse Equal Original
- C Make Calculator
- C Add Digits of Number
- Count Positive Negative Zero
- C Largest of Two Numbers
- C Largest of Three Numbers
- C Smallest of Two Numbers
- C Smallest of Three Numbers
- C Find Factorial of Number
- C Find LCM & HCF
- C Find LCM of n Numbers
- C Find HCF of n Numbers
- C Find Arithmetic Mean
- C Find Average, Percentage
- C Find Student Grade
- C Print Table of Number
- C Print Prime Numbers
- C Find Discount Purchase
- C Calculate Parcel Charge
- C Calculate Wage of Labor
- C Print Phone Bill
- C Conversion programs
- 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 Printing Programs
- C Print Diamond Pattern
- C Print Floyd's Triangle
- C Print Pascal's Triangle
- C Array Programs
- C 1D Array Programs
- C Linear Search
- C Binary Search
- C Largest Element in Array
- C Smallest Element in Array
- C Second Largest/Smallest
- C Count Even Odd
- C Array Element at Even
- C Array Element at Odd
- C Print Even Array Elements
- C Print Odd Array Elements
- C Sum/Product of Even/Odd
- C Reverse an Array
- C Insert Element in Array
- C Delete Element from Array
- C Merge Two Arrays
- C Bubble Sort
- C Selection Sort
- C Insertion Sort
- C Print Common Elements
- C 2D Array Programs
- C Add Two Matrices
- C Subtract Two Matrices
- C Transpose a Matrix
- C Multiply Two Matrices
- C Sum All Matrix Elements
- C Largest Element in Matrix
- C Print Row Column Total
- C 3D Array Programs
- C String Programs
- C Print String
- C Find Length of String
- C Compare Two String
- C Copy a String
- C Concatenate String
- C Reverse a String
- C Count Vowels Consonants
- C Replace Vowel in String
- C Delete Vowels from String
- C Delete Word from String
- C Frequency of Character
- C Count Word in String
- C Remove Spaces from String
- C Sort a String
- C Sort String in Alphabetical
- C Sort Words in Ascending
- C Sort Words in Descending
- C Uppercase to Lowercase
- C Lowercase to Uppercase
- C Swap Two Strings
- C Check Anagram or Not
- C Check Palindrome String
- C Print Number in Words
- C Print Successive Character
- C Character without Space
- C Remove Extra Spaces
- C File Programs
- C Read a File
- C Write Content to File
- C Read & Display File
- C Copy a File
- C Merge Two Files
- C Reverse File
- C Count All Character in File
- C List Files in Directory
- C Encrypt & Decrypt a File
- C Delete a File
- C Misc Programs
- Generate Random Numbers
- C Print Date Time
- C Print Message with Time
- C Get IP Address
- C Print Smiling face
- C Pass Array to Function
- Add Two Numbers using Pointer
- C Address of Variable
- C Shutdown Computer
- C Programming Tutorial
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- C Standard Library
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- All Test List
C Program to Merge Two Files
In this article, you will learn and get code about merging of two files. Merging two files means the content of any two files (entered by user at run-time) gets merged into the third file in a way that, the content of first source file gets copied to the target file, and then the content of second source file gets appended to the target file.
Things to Do before Program
Before going through the program, let's first create three files (inside the current directory) namely:
- codes.txt - as first source file
- cracker.txt - as second source file
- codescracker.txt - as target file
All the above files must be saved in a directory where you are saving (your previous programs) or going to save the program given below. Put the following content, inside codes.txt file:
I'm inside codes.txt file
And then put the following content, inside cracker.txt file:
I'm inside cracker.txt file
The third file named codescracker.txt remains blank (without any content). Because the program given below, merged the content of both the files namely codes.txt and cracker.txt into it. Because, I'm saving my source code file in a folder named c programs available to its parent directory Documents of C-Drive of my computer. So here is the snapshot of c programs folder:
Now let's move on to the program given below.
Merge the Content of Two Files in a Third File
The question is, write a program in C to merge two files and write it in a new file. The answer to this question is:
#include<stdio.h> #include<conio.h> int main() { FILE *fsOne, *fsTwo, *fTarget; char fName1[20], fName2[20], fName3[30], ch; printf("Enter the Name of First Source File: "); gets(fName1); printf("Enter the Name of Second Source File: "); gets(fName2); printf("\nEnter the Name of Target File: "); gets(fName3); fsOne = fopen(fName1, "r"); fsTwo = fopen(fName2, "r"); if(fsOne==NULL || fsTwo==NULL) { printf("\nError Occurred while Opening the Source File!"); } else { fTarget = fopen(fName3, "w"); if(fTarget==NULL) { printf("\nError Occurred while Opening the Target File!"); } else { ch = fgetc(fsOne); while(ch!=EOF) { fputc(ch, fTarget); ch = fgetc(fsOne); } ch = fgetc(fsTwo); while(ch!=EOF) { fputc(ch, fTarget); ch = fgetc(fsTwo); } printf("\n%s and %s Merged into %s Successfully!", fName1, fName2, fName3); } } fclose(fsOne); fclose(fsTwo); fclose(fTarget); getch(); return 0; }
This program was build and run under Code::Blocks IDE. Here is the initial snapshot of its sample run:
Now enter the name of two source files named codes.txt and cracker.txt that was created at the early of this article. And then enter the name of target file codescracker.txt to copy the content of both files into this file. Here is the sample run:
If you will open the file codescracker.txt, then you will see that the content of both the files is copied into it.
The two source files codes.txt and cracker.txt is opened in reading mode using r file opening mode. Because we have only to read the content inside these two files.
And the target file codescracker.txt is opened in writing mode using w file opening mode. Because we have to write something (content of both source file) into it.
What if File Doesn't Exist ?
In case, if any file doesn't exist or you have not the permission to access the file, then the function fopen() returns NULL. Therefore, before starting the operation, we have checked whether it returns NULL or not. If it returns NULL, then print an error message, otherwise continue the merge operation.
Using fgetc(), we can get the character using the FILE pointer fsOne and fsTwo one by one. And using fputc(), we can put the character to the file fTarget. Therefore, we have get the character one by one from both the file and put into the third file.
If all the content gets read, then at last, fgetc() function will return EOF (End-Of-File). So here also, we have compared whether the value of ch is equal to EOF or not. If it is not equal to EOF, then continue putting the character, otherwise exit the while loop
Note - After performing all the operation related to file, be sure to close its pointer using fclose() function.
Same Program in Other Languages
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