#include <string>
#include <iostream>
#include <stdlib.h>
#include <unistd.h>
#include <dirent.h>
#include <sys/wait.h>
using namespace std;
void showCommandLine(){
    char cwd[1024];
	/*write a command to fill swd with current directory path*/
	cout<<"12345678@"<<cwd<<"/ ";
}
void run(const char* par){						
	pid_t pid; 								
	int stat;
	/*implement me */
	wait(&stat);
}
void zombie(){
	pid_t pid = fork();				
	if (pid == 0){
		/* implement me*/
	}
	cout<<"zombie process created !\n";
}
void change_dir(const char* par){
	if(/* call a right function here */){			
		cout<<"unable to change directory to "<<par<<endl;
	}
}
int main(int argc, char **argv)	
{
	char ch;
	while(1){					
		string input="";
		showCommandLine();
		while((ch=cin.get())!='\n'){input+=ch;}	
		if(input.compare("quit")==0)return 0;
		if(input.find("list")==0){	
			run("/bin/ls");
		}
		else if(input.find("run")==0){
			run(input.c_str()+4);
		}		
		else if(input.find("chdir")==0){
			change_dir(input.c_str()+6);
		}	
		else if(input.find("zombie")==0){
			zombie();
		}
		else cout<<"command not found.\n";
	}
}