/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   eval.c                                             :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: charles <charles.cabergs@gmail.com>        +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2020/04/01 17:05:21 by charles           #+#    #+#             */
/*   Updated: 2020/06/14 10:34:11 by charles          ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

/* #<{(| */
/* ** \file   eval.c */
/* ** \brief  Evaluation of an AST */
/* |)}># */
/*  */
/* #include "eval.h" */
/*  */
/* #<{(| */
/* ** \brief          Wrap a function in a fork */
/* ** \param fd_in    fork input file descriptor */
/* ** \param fd_out   fork output file descriptor */
/* ** \param passed   param of the wrapped function */
/* ** \param wrapped  function to wrap */
/* |)}># */
/*  */
/* int			fork_wrap( */
/* 	int	fd_in, */
/* 	int fd_out, */
/* 	void *passed, */
/* 	int (*wrapped)(void *param)) */
/* { */
/* 	int		status; */
/* 	pid_t	child_pid; */
/*  */
/* 	if ((child_pid = fork()) == -1) */
/* 		return (-1); */
/* 	if (child_pid == 0) */
/* 	{ */
/* 		if (dup2(STDIN_FILENO, fd_in) == -1 || */
/* 			dup2(STDOUT_FILENO, fd_out) == -1) */
/* 			exit(EXIT_FAILURE); */
/* 		if ((status = wrapped(passed)) == -1) */
/* 			exit(EXIT_FAILURE); */
/* 		exit(status); */
/* 	} */
/* 	wait(&child_pid); */
/* 	return (WEXITSTATUS(child_pid)); */
/* } */
/*  */
/* int 		run_builtin(t_eval_state *state, char **argv) */
/* { */
/* 	return (builtin_dispatch_run(argv, state->env)); */
/* } */
/*  */
/* #<{(| */
/* ** \brief        execve syscall wrapper passed it to fork_wrap */
/* ** \param param  function params */
/* ** \return       execve return value */
/* |)}># */
/*  */
/* int 		execve_wrapper(void *param) */
/* { */
/* 	return (execve( */
/* 		((t_fork_param_execve*)param)->exec_path, */
/* 		((t_fork_param_execve*)param)->argv, */
/* 		((t_fork_param_execve*)param)->envp */
/* 	)); */
/* } */
/*  */
/* #<{(| */
/* ** \brief        Evaluate a command */
/* ** \param state  Evaluation state */
/* ** \param cmd    Command to evaluate */
/* ** \return       Executable status or -1 on error */
/* |)}># */
/*  */
/* static int	eval_cmd(int fd_in, int fd_out, t_eval_state *state, t_cmd *cmd) */
/* { */
/* 	t_fork_param_execve	param; */
/*  */
/* 	if (builtin_check_exec_name(cmd->argv[0])) */
/* 		return (run_builtin(state, cmd->argv)); */
/* 	param.exec_path = exec_search_path( */
/* 			state->path, env_search(state->env, "PATH"), cmd->argv[0]); */
/* 	if (param.exec_path == NULL) */
/* 		return (-1); */
/* 	if (cmd->in != NULL && (fd_in = open(cmd->in, O_RDONLY)) == -1) */
/* 		return (-1); */
/* 	if (cmd->out != NULL && (fd_out = open(cmd->out, */
/* 			(cmd->is_append ? O_APPEND : O_WRONLY) | O_CREAT)) == -1) */
/* 		return (-1); */
/* 	param.argv = cmd->argv; */
/* 	param.envp = (char**)state->env->data; */
/* 	return (fork_wrap(fd_in, fd_out, &param, &execve_wrapper)); */
/* } */
/*  */
/* #<{(| */
/* ** \brief        Evaluate a line */
/* ** \param state  State of the evaluation */
/* ** \param line   Line to evaluate */
/* ** \return       Last Executed command status or -1 on error */
/* |)}># */
/*  */
/* static int	eval_line(void *param) */
/* { */
/* 	int				status; */
/* 	t_eval_state	*state; */
/* 	t_line			*line; */
/* 	int fd_in; */
/* 	int fd_out; */
/*  */
/* 	state = ((t_fork_param_line*)param)->state; */
/* 	line = ((t_fork_param_line*)param)->line; */
/* 	fd_in = ((t_fork_param_line*)param)->fd_in; */
/* 	fd_out = ((t_fork_param_line*)param)->fd_out; */
/*  */
/* 	#<{(| if (line->right == NULL) |)}># */
/* 	#<{(| 	return (eval(state, line->left)); |)}># */
/*  */
/* 	#<{(| if (line->sep == SEP_PIPE) |)}># */
/* 	#<{(| 	pipe(state->p); |)}># */
/*  */
/* 	if (line->left->tag == AST_LINE) */
/* 	{ */
/* 		return (fork_wrap(fd_in, fd_out, param, &eval_line)); */
/* 	} */
/* 	if ((status = eval(fd_in, fd_out, state, line->left)) == -1) */
/* 		return (-1); */
/* 	if ((line->sep == SEP_AND && status != 0) || */
/* 		(line->sep == SEP_OR && status == 0)) */
/* 		return (status); */
/*  */
/* 	return (eval(fd_in, fd_out, state, line->right)); */
/* } */
/*  */
/* #<{(| */
/* ** \brief        Evaluate an AST */
/* ** \param state  State of the evaluation */
/* ** \param ast    Abstract syntax tree to evaluate */
/* ** \return       Last command status or -1 on error */
/* |)}># */
/*  */
/* int			eval(int fd_in, int fd_out, t_eval_state *state, t_ast *ast) */
/* { */
/* 	t_fork_param_line param; */
/*  */
/* 	errno = 0; */
/* 	if (ast->tag == TAG_LINE) */
/* 	{ */
/* 		param.state = state; */
/* 		param.line = &ast->line; */
/* 		param.fd_in = fd_in; */
/* 		param.fd_out = fd_out; */
/* 		return (eval_line(&param)); */
/* 	} */
/* 	if (ast->tag == TAG_CMD) */
/* 		return (eval_cmd(fd_in, fd_out, state, &ast->cmd)); */
/* 	return (-1); */
/* } */