Thread: Encrypting a txt file

I'm trying to figure out how to write out this code. These are the 3 steps...

1. Parent reads from a file “input.txt” and writes into a pipe A that connects to
child process #1.
2. Child process 1 reads from pipe A and add a value v, that is provided by the user as a command line argument, to each character read from the pipe. Child 1 then writes
the new character values into a second pipe B, which allows communication with child
process #2.
3. Child process 2 reads character by character from pipe B and writes the values
to a new file “output.txt”.

I think I have #1 done but I'm not sure if I can use the read command this way. I was wondering if it would actually be easier using fopen or fgets? I'm also wondering if I actually have to write out the encryption or this is an encrption command in some header.

Code:

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

int main(void)
{

	int fd[2];
	char buf[5];
	ssize_t nbytes;
	int status;
	

	status = pipe(fd);
	if (status == -1) {
		perror("fork");
		exit(1); }
	
	switch (fork()) {
	case -1: //Handle error
		break;

	case 0:  //Child reads from pipe
		close(fd[1]);				//Write end is unused
		nbytes = read(fd[0], buf, 100);    // Get data from pipe
		//close(fd[0]);
		exit(EXIT_SUCCESS);

	case 1:  // Another child
	
	default: //Parent-readms/writes to pipe
		  f = fopen("input.txt", "rt");
		  nbytes = read(fd[0], buf, 5);
   		  write(fd[1], s, 5);

I update my code. I need help with the character array. I'm not sure if I doing it right but im trying to get the program to ask the user to add a value to the character that is being displayed.

Code:

#include <unistd.h>
#include <sys/types.h>


int main()
{
	int fd[2]; 
	int nbytes;
	pid_t childpid;
	char garbage[30];
	int m;	

	pipe(fd);
	
		if((childpid = fork()) == -1)
		{
		perror("fork");
		exit(1);
		}
		  else	if(childpid == 0)
		{
			//Child process 1
			dup2(fd[0], 0);
			read(fd[0], garbage, sizeof garbage);
			while (printf("Character: %d", garbage[]), fgets(garbage, 30, stdin), !feof(stdin)){
			if
			}	
		else if(childpid > 0) 
		{	
			//Parent
			read(fd[#], "input.txt", "rb");
			write(fd[#], garbage, sizeof garbage);
			childpid = fork();
			if(childpid == -1){
			perror("fork");
			exit(1);
		}	
		 else if (childpid == 0)
		{
			//Child process 2
			close(fd[0]);
			dup2(fd[1], 1);
	
		}

return 0;