execute_child.c

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/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   execute_child.c                                    :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: rocky <marvin@42.fr>                       +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2024/11/06 16:28:49 by rocky             #+#    #+#             */
/*   Updated: 2024/11/06 16:28:51 by rocky            ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */
 
#include "builtins.h"
#include "libft.h"
#include <stdio.h>
#include <sys/wait.h>
#include "shell.h"
#include "execute.h"
#include "tokens.h"
#include "pipe.h"
#include "redirection.h"
#include "exit_status.h"
#include "signals.h"
#include "exit_status.h"
 
int         execute(t_ms_data *data);
static int  new_process(t_ms_data *data);
static void signal_handler(void);
static void handle_exec_errors(char *exec_path, t_ms_data *data);
 
int execute(t_ms_data *data)
{
    size_t  i;
    char    *builtin_commands[7];
    int     (*builtin_functions[7])(t_ms_data *);
 
    builtin_commands[0] = "cd";
    builtin_commands[1] = "echo";
    builtin_commands[2] = "env";
    builtin_commands[3] = "exit";
    builtin_commands[4] = "export";
    builtin_commands[5] = "pwd";
    builtin_commands[6] = "unset";
    builtin_functions[0] = &builtin_cd;
    builtin_functions[1] = &builtin_echo;
    builtin_functions[2] = &builtin_env;
    builtin_functions[3] = &builtin_exit;
    builtin_functions[4] = &builtin_export;
    builtin_functions[5] = &builtin_pwd;
    builtin_functions[6] = &builtin_unset;
    i = -1;
    while (++i < sizeof(builtin_commands) / sizeof(char *))
        if (ft_strcmp(data->args[0], builtin_commands[i]) == 0)
            return ((*builtin_functions[i])(data));
    return (new_process(data));
}
 
static void child_process(t_ms_data *data)
{
    char    *exec_path;
 
    handle_std_io(&data->std_in, STDIN_FILENO);
    handle_std_io(&data->std_out, STDOUT_FILENO);
    close_fds(data->std_in, data->std_out);
    signal_handler();
    if (ft_strncmp(data->args[0], "/", 1) == 0)
        exec_path = ft_strdup(data->args[0]);
    else
        exec_path = ft_find_path(data->args[0], data->envp);
    handle_exec_errors(exec_path, data);
}
 
static int  new_process(t_ms_data *data)
{
    pid_t   pid;
    int     exit;
 
    exit = 0;
    handle_std_io(&data->std_in, STDIN_FILENO);
    handle_std_io(&data->std_out, STDOUT_FILENO);
    pid = fork();
    if (pid == -1)
        ft_perror("fork");
    if (pid == 0)
        child_process(data);
    close_fds(data->std_in, data->std_out);
    waitpid(pid, &exit, 0);
    if (WIFSIGNALED(exit) && WTERMSIG(exit) == SIGQUIT)
        ft_printf("\n");
    return (WEXITSTATUS(exit));
}
 
static void handle_exec_errors(char *exec_path, t_ms_data *data)
{
    if (exec_path == NULL)
    {
        ft_putstr_fd("maxishell: command not found\n", STDERR_FILENO);
        exit(127);
    }
    if (!data->args || !data->args[0] || !data->envp)
    {
        ft_putstr_fd("maxishell: invalid \
            arguments or environment\n", STDERR_FILENO);
        exit(EXIT_FAILURE);
    }
    if (execve(exec_path, data->args, env_to_array(data->envp)) == -1)
    {
        ft_putstr_fd("maxishell: command not found\n", STDERR_FILENO);
        exit(IS_DIRECTORY);
    }
}
 
static void signal_handler(void)
{
    struct sigaction    a;
 
    ft_memset(&a, 0, sizeof(struct sigaction));
    sigemptyset(&a.sa_mask);
    a.sa_handler = SIG_DFL;
    a.sa_flags = 0;
    sigaction(SIGQUIT, &a, NULL);
}