getw() and putw() functions in C

getw() and putw() functions:

            getw() and putw() are number oriented functions are used to read and write integer values on a given file.

getw() function:                      getw() function is used to read an integer value from a given file.  The general format of the getw() function is:

            Syntax:            getw(FilePointer);

This function receives FilePointer as an argument and returns next integer from the input file.  It returns EOF whenever end of file has been reached.

putw() function:          putw() function is used to write an integer value into the specified file.  The general format of the putw() function is:

            Syntax:            putw(N,FilePointer);

Where,

            N is an integer value to be written into the given file with FilePointer opened in write mode.

/* WRITE A PROGRAM TO CREATE AN INPUT DATA FILE WHICH CONTAINS A LIST OF INTEGERS.  READ THE SAME DATA FROM THE FILE AND WRITE EVEN AND ODD NUMBERS INTO TWO SEPARTE FILES */

#include<stdio.h>

#include<conio.h>

main()

{

            int item,n,i;

            FILE *f1,*f2,*f3;

            clrscr();

            f1=fopen("input.dat","w");

            printf("\nEnter how many numbers:");

            scanf("%d",&n);

            printf("\nEnter %d Numbers:",n);

            for(i=1;i<=n;i++)

            {

                        scanf("%d",&item);

                        putw(item,f1);

            }

            fclose(f1);

            f1=fopen("input.dat","r");

            if(f1==NULL)

            {

                        printf("\nFILE OPENING ERROR");

                        exit();

            }

            f2=fopen("even.dat","w");

            f3=fopen("odd.dat","w");

            while((item=getw(f1))!=EOF)

            {

                        if(item%2==0)

                                    putw(item,f2);

                        else

                                    putw(item,f3);

            }

            fcloseall();

            printf("\nEVEN NUMBERS ARE:");

            f2=fopen("even.dat","r");

            while((item=getw(f2))!=EOF)

            printf("%6d",item);

            fclose(f2);

            printf("\nODD NUMBERS ARE:");

            f3=fopen("odd.dat","r");

            while((item=getw(f3))!=EOF)

            printf("%6d",item);

            fclose(f3);

}