#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <pwd.h>
#include <string.h>
#include <wait.h>

#define space " \n"
#define max_c 500

int help() {
    printf ("microshell v1.0. © 2018 Krystian Rzepa\n");
    printf("Obslugiwane polecenia:\n\
    help - pomoc\n\
    exit - wyjscie\n\
    cd - zmiana aktualnego katalogu\n\
    pwd - wyswietla aktualny katalog\n\
    obsluga programow z parametrami\n");
}


const char *getUserName()
{
  uid_t uid = geteuid();
  struct passwd *pw = getpwuid(uid);

  return pw->pw_name;
}


int main()
{
    char cwd[1000], hostName[100], *pwd[1000];
    register struct passwd *pw;
    register uid_t uid;
    uid = geteuid ();
    pw = getpwuid (uid);

    char line[max_c], lend[max_c], * commands[max_c], ** command;

    while (1) {
    gethostname(hostName, 99);
    getcwd(cwd, 999);

    printf("%s@%s %s $ ", pw->pw_name, hostName, cwd);

    fflush(stdout);
    if (fgets(line, max_c, stdin )) {

        command = commands;
        *command++ = strtok(line,space);
        while ((*command++ = strtok(NULL,space)));


    if (strcmp(commands[0], "help")==0) help();

    else if (strcmp(commands[0], "exit")==0) {
        if (commands[1]==0) exit(0);
        else exit(atoi(commands[1]));
    }

    else if (strcmp(commands[0], "cd")==0) {
        if (commands[1]==0) printf("Wymagany argument\n");
        int ret;
        ret = chdir(commands[1]);
        strcpy(lend, "pwd");
    }

    else if (strcmp(commands[0], "pwd")==0) printf ("%s\n", cwd);

    else {
        pid_t  x;
        x = fork();

        if (x==0) {
        if (commands[1] == 0) execlp(commands[0], commands[0], (char *)NULL);
        else execlp(commands[0], commands[0], commands[1], (char *)NULL);
        printf("Nie ma takiego polecenia. Wpisz help aby wyswietlic dostepne polecenia.\n");
        }
        else  waitpid(x, NULL, 0);

    }
    }
    }

    return 0;
}