Write a program to combine contents of two files in a third file. Add line number at the beginning of each line.
CODING:
#include <stdio.h>
#include<conio.h>
void main()
{
 FILE *fp1,*fp2,*fp3;
 char f1name[13],f2name[13],f3name[13];
 char ch;
 int a=1;
 clrscr();

 printf("\nEnter file 1 name : ");
 flushall(); gets(f1name);
 printf("Enter file 2 name : ");
 flushall(); gets(f2name);
 fp1=fopen(f1name,"r");
 fp2=fopen(f2name,"r");

 if(fp1==NULL || fp2==NULL)
 {
printf("\nFile(s) not found.");
getch();
exit();
 }
 printf("Enter new file name : ");
 flushall(); gets(f3name);
 fp3=fopen(f3name,"w");

 if(fp3==NULL)
 {
printf("\nError in creating file.");
getch();
exit();
 }
 fprintf(fp3,"%d. ",a++);

 while(!feof(fp1))
 {
ch=fgetc(fp1);
fputc(ch,fp3);

if(ch=='\n')
fprintf(fp3,"%d. ",a++);
 }
 fprintf(fp3,"\n%d. ",a++);

 while(!feof(fp2))
 {
ch=fgetc(fp2);
fputc(ch,fp3);

if(ch=='\n')
fprintf(fp3,"%d. ",a++);
 }
 printf("\nText in new file :\n");
 fcloseall();
 fp3=fopen(f3name,"r");

 while(!feof(fp3))
 {
ch=fgetc(fp3);
printf("%c",ch);
 }
 fcloseall();

 getch();
}