#include <stdio.h>
#include <iostream>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <vector>
#include <string>

using namespace std;

void Exec(vector<string>& command)
{
    int size = command.size();
    char** args = new char* [size + 1];
    args[size] = NULL;
    for (int i = 0; i < size; i++)
        args[i] = (char*)command[i].c_str();

    execvp(args[0], args);
}

vector< vector<string> > ParseCommands(char* buffer, int size)
{
    vector< vector<string> > commands;
    vector<string> empty;
    commands.push_back(empty);
    commands[0].push_back("");
    int k = 0, l = 0;
    for (int i = 0; i < size; i++)
    {
        if (buffer[i] == ' ')
        {
            if (commands[k][l].size() > 0)
            {
                commands[k].push_back("");
                l++;
            }
        }
        else if (buffer[i] == '|')
        {
            if (commands[k][l].size() <= 0)
                commands[k].pop_back();
            commands.push_back(empty);
            k++;
            commands[k].push_back("");
            l = 0;
        }
        else
            commands[k][l] += buffer[i];
    }
    return commands;
}

int main(int argc, char** argv)
{
    char buffer[1024];
    int size = read(STDIN_FILENO, buffer, 1024);

    vector< vector<string> > commands = ParseCommands(buffer, size);
    int k = 0;
    while (true)
    {
        if (k >= commands.size() - 1)
        {
            int fd = open("/home/box/result.out", O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);
            close(STDOUT_FILENO);
            dup2(fd, STDOUT_FILENO);
            close(fd);
            Exec(commands[k]);
            break;
        }
        int pfd[2];
        pipe(pfd);
        if ((pid = fork()))
        {
            close(STDOUT_FILENO);
            dup2(pfd[1], STDOUT_FILENO);
            close(pfd[1]);
            close(pfd[0]);

            waitpid(pid, NULL, 0);
            Exec(commands[k]);
            break;
        }
        else
        {
            close(STDIN_FILENO);
            dup2(pfd[0], STDIN_FILENO);
            close(pfd[1]);
            close(pfd[0]);
            k++;
        }
    }
    return 0;
}