main.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   main.c                                             :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: joaoteix <joaoteix@student.42.fr>          +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2023/02/22 10:02:10 by joaoteix          #+#    #+#             */
/*   Updated: 2023/04/28 15:49:44 by joaoteix         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "libft.h"
#include "pipex.h"
#include <stdlib.h>
#include <unistd.h>

// Close all pipes (should be called after using dup to copy necessary fds)
void	close_pipes(t_pipecon *context)
{
	int	i;

	close(context->pipes[0][0]);
	i = 1;
	while (i < (context->pipe_n - 1))
	{
		close(context->pipes[i][0]);
		close(context->pipes[i][1]);
		i++;
	}
	close(context->pipes[context->pipe_n - 1][1]);
}

// Create pipes
int	gen_pipes(t_pipecon *context, char *argv[], int argc)
{
	int	i;

	context->pipe_n = (argc - 2);
	context->pipes = malloc(sizeof(int [2]) * context->pipe_n);
	context->pipes[0][0] = open(argv[1], O_RDONLY);
	if (context->pipes[0][0] == -1)
	{
		ft_dprintf(2, "pipex: %s: %s\n", strerror(errno), argv[1]);
		context->pipes[0][0] = open("/dev/null", O_RDONLY);
	}
	i = 1;
	while (i < (context->pipe_n - 1))
		pipe(context->pipes[i++]);
	context->pipes[i][1] = open(argv[argc - 1], FILE_FLAG, ACCESS_BITS);
	if (context->pipes[i][1] == -1)
		ft_dprintf(2, "pipex: %s: %s\n", strerror(errno), argv[argc - 1]);
	return (context->pipes[i][1] != -1);
}

int	exec_pipe_chain(t_pipecon *context, char *argv[], char *envp[])
{
	int			i;
	int			pid;
	char		**path;

	path = ft_parse_path(envp);
	i = 0;
	while (i < (context->pipe_n - 1))
	{
		context->pipe_i = i;
		pid = ft_proc_cmd(context, argv[i + 2], path, envp);
		i++;
	}
	ft_free_str_arr(path);
	return (pid);
}

int	main(int argc, char *argv[], char *envp[])
{
	int			wstatus;
	int			last_pid;
	t_pipecon	context;

	if (argc != 5)
		return (EXIT_FAILURE);
	if (!gen_pipes(&context, argv, argc))
	{
		free(context.pipes);
		return (EXIT_FAILURE);
	}
	last_pid = exec_pipe_chain(&context, argv, envp);
	close_pipes(&context);
	free(context.pipes);
	if (last_pid < 0)
		return (127);
	waitpid(last_pid, &wstatus, 0);
	return (WEXITSTATUS(wstatus));
}