/*
 * Program: This is a shell that reports stats of running times of processes initiated in 
 * the shell as well as the shell itself's process time 
 */
 
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/times.h>
#include <sys/stat.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <sys/socket.h>
#include <signal.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <string>
#include <iostream>
#include <iomanip>
#include <cstdlib>
 
using namespace std;
 
/**
 *  method displayID
 *  returns: nothing
 *  parameters: none
 *  Description: This method displays the author information
 */
 
void displayID()
{
}
 
/**
 *  method displayInfo
 *  returns: nothing
 *  parameters: none
 *  Description: This method displays the Game info
 */
 
void displayInfo()
{
        cout << "The function of the shell is to operate child processes" << endl;
	cout << "And return statistics of process time of each process" << endl;
	cout << "That has been running in the shell as well as the shell's" << endl;
	cout << "process time" << endl;
}
 
 
/**
 *  method takeInpt
 *  returns: nothing
 *  parameters: none
 *  Description: This method takes the input for the shell
 */
 
void takeInpt(char* cmnd, char* cmd[], char inpt[])
{
	//ask for and get the input	
        cout << "statsh$: ";
        cin.getline(inpt,81);
	cmnd = strtok(inpt, " ");
	int c = 0;
 
	while(cmnd != NULL)
	{
	    cmd[c] = cmnd;
	    c++;
	    cmnd = strtok(NULL, " ");
	}
}
 
/**
 *  method runProc  
 *  returns: nothing
 *  parameters: none
 *  Description: This method runs exec and forking commands
 */
 
void runProc(char* cmd[])
{
    pid_t pid;
 
    // fork
    / /do i check for bad input here??!! 
    pid = fork();
    if(pid < 0)
    {
	cout << "Fork Failed" << endl;
	exit(-1);
    }
    else if( pid == 0)
    {
	execvp(cmd[0], cmd);
    }
    else 
    {
	wait(NULL);
	cout << "Job's Done" << endl;
    }
 
}
 
int main()
{
   char* cmnd;
   char* cmd[40];
   char inpt[81]; 
 
   displayID();
   displayInfo();
 
   while(1)
   {
        //clean out the array each time
        for(int m=0; m < 40; m++)
        {
             cmd[m] = NULL;
        }
 
   	takeInpt(cmnd, cmd, inpt);
 
        if(cmd[0] == NULL)
        {
             cout << "Enter a command please" << endl;
        }
   	else if(strcmp(cmd[0], "exit") == 0 )
   	{
             break;
   	}
	else
	{
            runProc(cmd);
	}
	/*
	 * testing print statement to see user input is taken and tokenized   
   	for(int i=0; i < 40; i++)
   	{
       	     if(cmd[i])
       	     {
           	  cout<< cmd[i] << endl;
       	     }
   	}
	*/
   }
 
   return 1;
 
}

void runProc(char* cmd[], int argSz) //argSz should be the max amount of args they entered counted in another method
{
    tms strt, end;
    long s,e;
    pid_t pid;
    bool badEx = false;
 
    for(int i=0; i < argSz; i++)   
    {
        //cout << "What's wrong here" << endl;
        if(getenv(cmd[i]) == NULL)
        {
            cout << "The error occured at: " << i << endl;
            badEx = true;  
            break;
        }
    }
    if(badEx == true)
    {
        cerr << "Bad Command or file name" << endl;
    }
    else
    {
    // fork
    times(&strt);   
    pid = fork();   
    switch(pid) 
    {
        case -1:
            cout << "Fork Failed" << endl;
            exit(-1);
        case  0:   
            execvp(cmd[0], cmd);
 
        default: 
 
            wait(NULL);
            times(&end);
            cout << "Process took: " << (end.tms_utime-strt.tms_utime)/100;
            cout << " seconds" << endl;
            cout << "Child has finished" << endl;
    }
} //end else

char * pathstr = getenv("PATH");

#include <stdlib.h>
#include <stdio.h>
 
int main(void) {
 
  char * s = getenv("PATH");
 
  if (s) {
    printf("%s\n", s);
  }
 
  return 0;
}

// fork
    times(&strt);
    pid = fork();
    switch(pid)
    {
        case -1:  
            cout << "Fork Failed" << endl;
            exit(-1);
        case  0:
            execvp(cmd[0], cmd);
 
            if(execvp(cmd[0], cmd) == -1)
            {
                cout << "Command Not Found" << endl;
                exit(0);
            }
 
        default:  
 
            wait(NULL);
            times(&end);
            cout << "Process took: " << (end.tms_utime-strt.tms_utime)/100;
            cout << " seconds" << endl;   
            cout << "Child has finished" << endl;
    }