microshell/microshell.c at main · Vidal-m/microshell · GitHub

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#include <sys/wait.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>

int	ft_strlen(char *s)
{
	int	len;

    len = -1;
	while (s[++len])
		;
	return (len);
}

int	cd(char **arg)
{
	if (!arg[1] || arg[2])
		return (write(2, "error: cd: bad arguments\n", 25), 1);
	else if (!chdir(arg[1]))
		return (0);
	write(2, "error: cd: cannot change directory to ", 38);
	write(2, arg[1], ft_strlen(arg[1]));
	return (write(2, "\n", 1));
}

int	exec_it(char **av, char **env)
{
	int	ret;
	int	pid;

	ret = 0;
	pid = -1;
	if (!av || !av[0])
		return (ret);
	if (!strcmp("cd", av[0]))
		return (cd(av));
	pid = fork();
	if (!pid)
	{
		execve(av[0], av, env);
		write(2, "error: cannot execute ", 22);
		write(2, av[0], ft_strlen(av[0]));
		exit(write(2, "\n", 1));
	}
	waitpid(pid, &ret, 0);
	return (WEXITSTATUS(ret));
}

int	main(int ac, char **av, char **env)
{
	int	fds[2];
	int	start;
	int	pid;
    int ret;
	int	c;

	start = 0;
	pid = -1;
	ret = 0;
	c = -1;
	av++;
	if (ac < 2)
		return (ret);
	while (av[++c])
	{
		if (!strcmp(";", av[c]))
		{
			av[c] = NULL;
			exec_it(&av[start], env);
			start = c + 1;
		}
		else if (!strcmp(av[c], "|"))
		{
			av[c] = NULL;
			pipe(fds);
			pid = fork();
			if (!pid)
			{
				dup2(fds[1], STDOUT_FILENO);
				close(fds[0]);
				close(fds[1]);
				exec_it(&av[start], env);
				exit(0);
			}
			dup2(fds[0], STDIN_FILENO);
			close(fds[0]);
			close(fds[1]);
			waitpid(pid, NULL, 0);
			start = c + 1;
		}
	}
	if (start < c)
		ret = exec_it(&av[start], env);
	return (ret);
}