From f573db414f297c2d439b118949bc3cf55165b514 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Luk=C3=A1=C5=A1=20Ji=C5=99i=C5=A1t=C4=9B?=
 <jiriste@icpf.cas.cz>
Date: Wed, 28 Aug 2024 09:59:34 +0200
Subject: [PATCH] Make subshell execute in a new process

Because the OS keeps track of CWDs of its processes, subshell is made to
run in its own process not to change the CWD of main shell.
Also make exit the last executed command in a pipeline and in a program.
---
 inc/minishell_structs.h |  3 ++-
 src/env.c               |  3 ++-
 src/execution.c         | 48 +++++++++++++++++------------------------
 src/main.c              |  5 +++--
 4 files changed, 27 insertions(+), 32 deletions(-)

diff --git a/inc/minishell_structs.h b/inc/minishell_structs.h
index 5c9f5ba..e3894c7 100644
--- a/inc/minishell_structs.h
+++ b/inc/minishell_structs.h
@@ -6,7 +6,7 @@
 /*   By: ljiriste <ljiriste@student.42prague.com>   +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2024/08/26 09:08:46 by ljiriste          #+#    #+#             */
-/*   Updated: 2024/08/27 16:59:59 by ljiriste         ###   ########.fr       */
+/*   Updated: 2024/08/28 09:36:55 by ljiriste         ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -32,6 +32,7 @@ typedef struct s_execution_env
 	int		stdout_fd;
 	int		ret_val;
 	int		exit;
+	int		subshell;
 	int		last_was_builtin;
 	int		last_builtin_ret_val;
 	t_vars	*vars;
diff --git a/src/env.c b/src/env.c
index 44d2a30..7f6dac8 100644
--- a/src/env.c
+++ b/src/env.c
@@ -6,7 +6,7 @@
 /*   By: ljiriste <marvin@42.fr>                    +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2024/07/21 21:24:52 by ljiriste          #+#    #+#             */
-/*   Updated: 2024/08/27 16:37:47 by ljiriste         ###   ########.fr       */
+/*   Updated: 2024/08/28 09:36:37 by ljiriste         ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -23,6 +23,7 @@ int	init_env(t_execution_env *env, char **envp)
 	env->ret_val = 0;
 	env->exit = 0;
 	env->last_was_builtin = 0;
+	env->subshell = 0;
 	env->vars = malloc(sizeof(t_vars));
 	if (!env->vars)
 		return (1);
diff --git a/src/execution.c b/src/execution.c
index 9a07f82..a3ba582 100644
--- a/src/execution.c
+++ b/src/execution.c
@@ -6,7 +6,7 @@
 /*   By: lnikolov <lnikolov@student.42prague.com    +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2024/07/21 08:57:54 by ljiriste          #+#    #+#             */
-/*   Updated: 2024/08/27 16:59:59 by ljiriste         ###   ########.fr       */
+/*   Updated: 2024/08/28 09:54:48 by ljiriste         ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -934,45 +934,37 @@ t_ft_stat	v_copy_redir(void *v_dest, const void *v_src)
 	return (success);
 }
 
-int	copy_env(t_execution_env *copy, const t_execution_env *env)
-{
-	*copy = *env;
-	copy->vars = malloc(sizeof(t_vars));
-	if (!copy->vars)
-		return (1);
-	ft_vec_init(&copy->vars->exported, sizeof(char *));
-	ft_vec_init(&copy->vars->other, sizeof(char *));
-	ft_vec_copy(&copy->vars->exported, &env->vars->exported, v_strcopy, free);
-	ft_vec_copy(&copy->vars->other, &env->vars->other, v_strcopy, free);
-	return (0);
-}
-
-void	free_env(t_execution_env *env)
-{
-	clean_vars(env->vars);
-	free(env->vars);
-	return ;
-}
-
 int	ex_program(t_parse_tree_node *program, t_execution_env *env);
 
 int	subshell(t_parse_tree_node *program, t_execution_env *env)
 {
-	int					res;
-	t_execution_env	env_copy;
+	int		res;
+	int		status;
+	pid_t	pid;
 
-	if (copy_env(&env_copy, env))
+	pid = fork();
+	if (pid == 0)
+	{
+		env->subshell = 1;
+		res = ex_program(program, env);
+		env->exit = 1;
+		return (res);
+	}
+	else if (pid < 0)
 		return (1);
-	res = ex_program(program, &env_copy);
-	env->ret_val = env_copy.ret_val;
-	free_env(&env_copy);
-	return (res);
+	waitpid(pid, &status, 0);
+	if (!WIFEXITED(status))
+		return (1);
+	env->ret_val = WEXITSTATUS(status);
+	return (0);
 }
 
 int	ex_command(t_parse_tree_node *command, t_execution_env *env)
 {
 	t_parse_tree_node	*comp_command;
 
+	if (env->exit)
+		return (0);
 	if (is_token_type(ft_vec_caccess(&command->children, 0), "simple_command"))
 		return (ex_simple_command(ft_vec_access(&command->children, 0), env));
 	else
diff --git a/src/main.c b/src/main.c
index 7231928..337843e 100644
--- a/src/main.c
+++ b/src/main.c
@@ -6,7 +6,7 @@
 /*   By: ljiriste <marvin@42.fr>                    +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2024/04/26 13:11:47 by ljiriste          #+#    #+#             */
-/*   Updated: 2024/08/27 15:08:06 by ljiriste         ###   ########.fr       */
+/*   Updated: 2024/08/28 09:38:51 by ljiriste         ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -56,10 +56,11 @@ int	main(int argc, __attribute__((unused)) char **argv, char **envp)
 		handle_input(&line, &env);
 		free(line);
 	}
+	if (!env.subshell)
+		ft_printf("exit\n");
 	res = env.ret_val;
 	clean_env(&env);
 	parse(NULL, NULL);
 	terminate_input();
-	ft_printf("exit\n");
 	return (res);
 }
-- 
2.30.2