how to take inputs and give outputs from a file in c

1#include<stdio.h>
2
3int main()
4{
5    FILE *fp;
6    char ch;
7    fp = fopen("one.txt", "w");
8    printf("Enter data...");
9    while( (ch = getchar()) != EOF) {
10        putc(ch, fp);
11    }
12    fclose(fp);
13    fp = fopen("one.txt", "r");
14 
15    while( (ch = getc(fp)! = EOF)
16    printf("%c",ch);
17    
18    // closing the file pointer
19    fclose(fp);
20    
21    return 0;
22}