pipex_util.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   pipex_util.c                                       :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: mring <mring@student.42heilbronn.de>       +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2024/05/07 16:11:39 by mring             #+#    #+#             */
/*   Updated: 2024/05/10 16:13:48 by mring            ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "pipex.h"

int	ft_strchr_i(const char *s, int c)
{
	unsigned int	i;

	i = 0;
	while (s[i])
	{
		if (s[i] == (char) c)
			return (i);
		i++;
	}
	if (s[i] == (char) c)
		return (i);
	return (-1);
}

char	*join_path(char *path, char *bin)
{
	char	*joined;
	int		i;
	int		j;

	joined = malloc(sizeof(char)
			* (ft_strchr_i(path, 0) + ft_strchr_i(bin, 0) + 2));
	i = 0;
	j = 0;
	while (path[j])
		joined[i++] = path[j++];
	joined[i++] = '/';
	j = 0;
	while (bin[j])
		joined[i++] = bin[j++];
	joined[i] = 0;
	return (joined);
}

char	*ft_strndup(char *str, unsigned int n)
{
	char				*s;
	unsigned int		i;

	i = 0;
	s = malloc(sizeof(char) * (n + 1));
	while (i < n)
		s[i++] = *str++;
	s[n] = 0;
	return (s);
}

char	*get_path(char *cmd, char **envp)
{
	char	*path;
	char	*dir;
	char	*bin;
	int		i;

	i = 0;
	while (envp[i] && ft_strncmp(envp[i], "PATH=", 5))
		i++;
	if (!envp || !envp[i])
		return (join_path("/usr/bin/", cmd));
	path = envp[i] + 5;
	while (path && ft_strchr_i(path, ':') > -1)
	{
		dir = ft_strndup(path, ft_strchr_i(path, ':'));
		bin = join_path(dir, cmd);
		free(dir);
		if (access(bin, F_OK) == 0)
			return (bin);
		free(bin);
		path += ft_strchr_i(path, ':') + 1;
	}
	return (cmd);
}