programming-examples/c/Data_Input_Output/C Program to Join Lines of Two given Files and Store them in a New file.c

/*
 * C Program to Join Lines of Two given Files and
 * Store them in a New file
 */
#include <stdio.h>
#include <stdlib.h>

/* Function Prototype */
int joinfiles(FILE *, FILE *, FILE *);

char ch;
int flag;

void main(int argc, char *argv[])
{
    FILE *file1, *file2, *target;
    file1 = fopen(argv[1], "r");
    if (file1 == NULL)
        {
            perror("Error Occured!");
        }
    file2 = fopen(argv[2], "r");
    if (file2 == NULL)
        {
            perror("Error Occured!");
        }
    target = fopen(argv[3], "a");
    if (target == NULL)
        {
            perror("Error Occured!");
        }
    joinfiles(file1, file2, target);        /* Calling Function */
    if (flag == 1)
        {
            printf("The files have been successfully concatenated\n");
        }
}

/* Code join the two given files line by line into a new file */

int joinfiles(FILE *file1, FILE *file2, FILE *target)
{
    while ((fgetc(file1) != EOF) || (fgetc(file2) != EOF))
        {
            fseek(file1, -1, 1);
            while ((ch = fgetc(file1)) != '\n')
                {
                    if (ch == EOF)
                        {
                            break;
                        }
                    else
                        {
                            fputc(ch, target);
                        }
                }
            while ((ch = fgetc(file2)) != '\n')
                {
                    if (ch == EOF)
                        {
                            break;
                        }
                    else
                        {
                            fputc(ch, target);
                        }
                }
            fputc('\n', target);
        }
    fclose(file1);
    fclose(file2);
    fclose(target);
    return flag = 1;
}

/*
The files have been successfully concatenated

/* FIRST FILE */

/*
Hello!!
This is a C Program File.
Consider a code to Add two numbers
*/

#include <stdio.h>
/* Function Prototype */
int sum(int,  int);
void main()
{
    int num1, num2;
    printf("Enter Number1 and Number2:");
    scanf("%d %d ", num1, num2);
    sum(num1, num2);
}

int sum(int a, int b)
{
    return a + b;
}

/* SECOND FILE */

/*
 * this is temporary file for use in file handling
 */
#include <stdio.h>

int sqrt(int);
void main()
{
    int num;
    printf("enter the number:");
    scanf("%d", &num);
    sqrt(num);
    printf("The square of the given number is:", num);
}
int sqrt(int num)
{
    return num*num;
}

/* CONCATENATED FILE */
/*
Hello!! * this is temporary file for use in file handling
This is a C Program File. *
Consider a code to Add two numbers  */
*/
#include <stdio.h>
#include <stdio.h>
int sqrt(int);
/* Function Prototype */void main()
{
    int sum(int,  int);
    int num;
    void main()    printf("enter the number:");
    {
        scanf("%d", &num);
        int num1, num2;
        sqrt(num);
        printf("Enter Number1 and Number2:");
        printf("The square of the given number is:", num);
        scanf("%d %d ", num1, num2);
    }
    sum(num1, num2);
    int sqrt(int num)
}
{
    return num*num;
    int sum(int a, int b)
}
{
    return a + b;
}