minishell/srcs/exec.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   exec.c                                             :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: tmaze <tmaze@student.42.fr>                +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2018/11/27 15:32:29 by tmaze             #+#    #+#             */
/*   Updated: 2019/01/24 13:41:09 by tmaze            ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "minishell.h"

#define S_BIN	5

char	**envlsttotab(t_list *env)
{
	size_t		i;
	size_t		env_size;
	t_list		*tmp;
	char		**ret;

	i = 0;
	tmp = env;
	env_size = ft_lstsize(env);
	if ((ret = (char**)ft_memalloc(sizeof(char*) * (env_size + 1))) == NULL)
		return (NULL);
	while (i <= env_size)
		ret[i++] = NULL;
	i = 0;
	while (tmp)
	{
		if ((ret[i] = ft_strnew(ft_strlen(((t_envelem*)(tmp->content))->key)
				+ ft_strlen(((t_envelem*)(tmp->content))->val) + 1)) == NULL)
		{
			ft_del_words_tables(&ret);
			return (NULL);
		}
		i++;
		tmp = tmp->next;
	}
	return (ret);
}

/*
** , {"setenv", &cmd_senv}, {"unsetenv", &cmd_senv}, {"env", &cmd_env}};
*/

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

	i = 0;
	while (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);
}

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

	if (ft_isin(exec, '/') != -1 && ft_isin(exec, '.') == -1)
	{
		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);
	}
	return (NULL);
}

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

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

char	*check_path(char *exec, t_list *env)
{
	size_t		i;
	t_envelem	*path;
	char		**path_elems;
	char		*tmp;
	char		*ret;

	i = 0;
	ret = NULL;
	if ((ret = check_path_slash(exec)) != NULL)
		return (ret);
	if ((ret = check_path_dot(exec, env)) != NULL)
		return (ret);
	if ((path = env_getelemfromkey("PATH", env)) == NULL
		|| path->val == NULL)
		return (NULL);
	if ((path_elems = ft_strsplit(path->val, ':')) == NULL)
		return (NULL);
	while (path_elems[i])
	{
		if ((tmp = ft_strjoin(path_elems[i], "/")) == NULL)
			put_error(exec, "memory error");
		if (tmp == NULL)
			break ;
		if ((ret = ft_strjoin(tmp, exec)) == NULL)
		{
			put_error(exec, "memory error");
			ft_strdel(&tmp);
			break ;
		}
		ft_strdel(&tmp);
		if (access(ret, F_OK) == 0)
		{
			if (access(ret, X_OK) == 0)
				break ;
			put_error(exec, "permission denied");
		}
		ft_strdel(&ret);
		i++;
	}
	if (path_elems[i] == NULL)
		put_error(exec, "command not found");
	ft_del_words_tables(&path_elems);
	return (ret);
}

int		exec_cmd(char **argv, t_list **env)
{
	int					ret;
	char				**env_tab;
	char				*path;
	size_t				i;
	static t_builtin	builtins[S_BIN] = {{"echo", &cmd_echo},
						{"cd", &cmd_cd}, {"setenv", &cmd_setenv},
						{"env", &cmd_env}, {"unsetenv", &cmd_unsetenv}};

	i = 0;
	while (i < S_BIN)
		if (ft_strcmp(argv[0], builtins[i++].cmd) == 0)
			return ((*(builtins[i - 1].f))(argv, env));
	if ((env_tab = envlsttotab(*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)
	{
		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);
		exit(-1);
	}
	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);
}