minishell/srcs/ms_exec.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ms_exec.c                                          :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: tmaze <tmaze@student.42.fr>                +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2019/09/26 16:25:00 by tmaze             #+#    #+#             */
/*   Updated: 2020/01/30 11:48:25 by tmaze            ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "minishell.h"

int		ft_isin(char *str, char c)
{
	int	i;

	i = 0;
	while (str && str[i])
		if (str[i++] == c)
			return (i - 1);
	return (-1);
}

void	*put_error(char *file, char *msg)
{
	ft_putstr("minishell: ");
	ft_putstr(file);
	ft_putstr(": ");
	ft_putendl(msg);
	return (NULL);
}

char	*check_path_slash(char *exec)
{
	int			i;
	struct stat	info;

	if ((i = access(exec, F_OK)) != 0)
		put_error(exec, "no such file or directory");
	if (i != 0)
		return (NULL);
	if ((i = stat(exec, &info)) != 0)
		put_error(exec, "can't determine info");
	if (i != 0)
		return (NULL);
	if (!S_ISREG(info.st_mode))
	{
		put_error(exec, "not an executable file");
		return (NULL);
	}
	if ((i = access(exec, X_OK)) != 0)
		put_error(exec, "permission denied");
	if (i != 0)
		return (NULL);
	return (exec);
}

char	*check_path_dot(char *exec, t_env *env)
{
	t_env	*path;
	char	*tmp;
	char	*ret;

	if ((path = ft_envgetelem("PWD", env)) == NULL
		|| path->val == NULL || (tmp = ft_strjoin(path->val, "/")) == NULL)
		return (put_error(exec, "memory error"));
	if ((ret = ft_strjoin(tmp, exec)) == NULL)
		put_error(exec, "memory error");
	ft_strdel(&tmp);
	if (ret == NULL)
		return (NULL);
	if (access(ret, F_OK) == 0)
	{
		if (access(ret, X_OK) == 0)
			return (exec);
		ft_strdel(&ret);
		return (put_error(exec, "permission denied"));
	}
	ft_strdel(&ret);
	return (put_error(exec, "no such file or directory"));
}

void	*ft_strdel_null(char **s)
{
	ft_strdel(s);
	return (NULL);
}

char	*check_path_elems(char **path_elems, char *exec)
{
	int		i;
	char	*tmp;
	char	*ret;

	i = -1;
	ret = NULL;
	while (path_elems[++i])
	{
		if ((tmp = ft_strjoin(path_elems[i], "/")) == NULL
			&& !put_error(exec, "memory error"))
			break ;
		if ((ret = ft_strjoin(tmp, exec)) == NULL
			&& !put_error(exec, "memory error") && !ft_strdel_null(&tmp))
			break ;
		if (!ft_strdel_null(&tmp) && access(ret, F_OK) == 0)
		{
			if (access(ret, X_OK) == 0)
				break ;
			ft_strdel(&ret);
			ft_del_words_tables(&path_elems);
			return (put_error(exec, "permission denied"));
		}
		ft_strdel(&ret);
	}
	return (ret);
}

char	*check_path(char *exec, t_env *env)
{
	size_t	i;
	t_env	*path;
	char	**path_elems;
	char	*ret;

	ret = NULL;
	if (exec)
	{
		if (ft_isin(exec, '/') != -1 && ft_isin(exec, '.') == -1)
			return (check_path_slash(exec));
		if (exec[0] == '.')
			return (check_path_dot(exec, env));
		if ((path = ft_envgetelem("PATH", env)) == NULL
			|| path->val == NULL
			|| (path_elems = ft_strsplit(path->val, ':')) == NULL)
			return (put_error(exec, "could not resolve path"));
		i = 0;
		if ((ret = check_path_elems(path_elems, exec)) == NULL)
		{
			ft_del_words_tables(&path_elems);
			return (put_error(exec, "command not found"));
		}
		ft_del_words_tables(&path_elems);
	}
	return (ret);
}

void	exec_cmd_child(char *path, char **argv, char **env_tab, t_env **env)
{
	execve(path, argv, env_tab);
	ft_putendl_fd("minishell: error", 1);
	if (ft_strcmp(path, argv[0]) != 0)
		ft_strdel(&path);
	ft_del_words_tables(&env_tab);
	ft_envdel(env);
	exit(-1);
}

int		exec_cmd(char **argv, t_env **env)
{
	int		ret;
	char	**env_tab;
	char	*path;

	if ((env_tab = ft_envtotab(*env)) == NULL)
		return (-1);
	if ((path = check_path(argv[0], *env)) == NULL)
		ft_del_words_tables(&env_tab);
	if (path == NULL)
		return (-1);
	if ((ret = fork()) == 0)
		exec_cmd_child(path, argv, env_tab, env);
	else if (ret == -1)
		ft_putendl_fd("minishell: error", 1);
	if (ret == -1)
		return (-1);
	waitpid(ret, NULL, 0);
	ft_del_words_tables(&env_tab);
	if (ft_strcmp(path, argv[0]) != 0)
		ft_strdel(&path);
	return (0);
}