Appending Text in a File in C

Appending to a file means adding at the end of the file while keeping the previous contents of the file intact. For this the file open mode is “a”. Program illustrates appending a file.

#include <stdio.h> 
 #include <stdlib.h> 
 void main() 
 { 
    FILE* fptr; 
    char ch; 
    fptr = fopen("File1.txt", "w"); 
    clrscr(); 
    if(fptr ==NULL) 
    { 
       printf("File1 could not be opened."); 
       exit (1); 
    } 
    else 
     { 
        printf("File1 is open. Enter a sentence.\n"); 
        while ((ch= getchar()) != EOF) 
        fputc(ch, fptr); 
        fclose(fptr); 
     } 
        fptr = fopen("File1", "a"); 
        if (fptr == NULL) 
        { 
          printf("File1 could not be opened"); 
          exit(1); 
        } 
        else  
        { 
           printf("File1 is open for appending.\nWrite a sentence.\n"); 
           while ((ch= getchar()) != EOF) 
             fputc(ch, fptr); 
             fclose(fptr); 
        } 
        fptr = fopen("File1", "r"); 
        printf("After appending contents of File1 are as below.\n"); 
        while ((ch = fgetc (fptr)) != EOF) 
           printf("%c",ch); 
           fclose(fptr); 
 }