Write a C program that will write input into a file, then it will return frequency of each letter occurred in the file.

Underlying Concept: File Handling

Note: Press CTRL-D for taking EOF as input

#include<stdio.h>

#include<stdlib.h>

#include<string.h>

int main()

{

        FILE *f1,*f2;

        char ch,bh;

        printf("\n write to file INPUT.txt:\n");

        f1=fopen("FREQUENCY.txt","w");

        while((ch=getchar())!=EOF)

                putc(ch,f1);

        fclose(f1);

    int n=0;

    f2=fopen("histogram.txt","w");

    unsigned char r;

    printf("\n\n");

   

    for(r=97;r<122;r++)

    {

        n=0;

        if(r%5==0)

            printf("\n");

        f1=fopen("FREQUENCY.txt","r");

        while((ch=getc(f1))!=EOF)

        {

            if(ch==r)

                n++;

        }

   

            printf(" Frequency of %c is %d\t",r,n);

            fprintf(f2,"%d",n);

            fprintf(f2,"\n");

        fclose(f1);

    }

    fclose(f2);

    return 0;

}