Building a Shell. I'm in Hell
 

So I'm trying to build a shell, and I've been stuck for days just trying to think about how to take in the input from the user. I need to be able to have a list of dynamically growing commands, that each has its list of dynamically growing arguments, so that I can handle situations where pipes occur, or regular commands occur with arguments, or redirections etc.

my first idea was make a struct of command types that held the char* command name, an array of arguments, and the size for the array of args. I could then make a vector of this. This idea seems pretty difficult to do though

The second idea was make a vector of vectors of char*s. so like
vector< <vector<char*> >, but this gives me errors like ISO C++ forbids items with no type. So i guess I cannot declare a vector of vectors? or am I declaring it wrong.

I want the easiest possible way to do this, because I am just stuck on it for three days straight now.

If someone could help me I would much appreciate it.

Re: Building a Shell. I'm in Hell
 

You're declaring it wrong; that'd be vector< vector<char *> >

Re: Building a Shell. I'm in Hell
 

okay so problem with this vector of vector of chars is it prnts me garbage when i test it

I have the take input functoin here:

takeInpt(vector< vector<char*> > &cmds)

{

        char inpt[255];

        char* cmnd;

        int count=0;

        vector<char*> in;



        //ask for and get the input        

        cout << "statsh$: ";

        

        cin.getline(inpt,255); //leave plenty of room for input



        cmnd = strtok(inpt, " "); 



        //first thing should be some command

        in.push_back(cmnd);        

        

        //all the rest will either be commands or arguments

        cmnd = strtok(NULL, " "); //get next item

        

            while(cmnd != NULL)

            {

                count=1; //gotten first command looking for arguments

        

                if(strcmp(cmnd,"|") == 0)

                {

                    piped = true;

                    cmnd = strtok(NULL, " "); //go over the pipe and get next token

               

                    if(cmnd != NULL)

                    {

                        cmds.push_back(in);

                        vector<char*> pipe;

                        in = pipe;

                        //fill command with relevant information

                        in.push_back(cmnd);

                    }

                    else

                    {

                        cerr << "You didn't pipe into anything" << endl;

                    }

                }

                else if(strcmp(cmnd,">") == 0)

                {

                    cmnd = strtok(NULL, " "); //go over > and get next token     

                    if(cmnd != NULL)

                    {

                        redFile = cmnd; //first redirection file 

                        redType = STDOUT;

                    } 

                        else 

                        {

                              cerr<< "Redirect to what now?? " << endl;

                        }

                } 

                else if (strcmp(cmnd, "<") == 0) 

                {

            

                    cmnd = strtok (NULL, " "); //go over < and get next token



                        if (cmnd != NULL)

                        {

                        redFile = cmnd;

                        redType = STDIN;

                    }   

                        else 

                        {

                        cerr<<  "Redirect what now?? " << endl;

                        }

                }

        

                else //get arguments to the current command

                {

                     in.push_back(cmnd);

                }

                cmnd = strtok(NULL, " ");

        }



        cmds.push_back(in);

        

        return count; //return size of input

  

}

From main i call the following:

int main()

{

   tms systemTime;

   clock_t sysTime;



   int argNums = 0;

   char* cmnd;

   vector< vector<char*> > commands;

  

   //init link list ignore for now

   lnkLst* head;

   head = new lnkLst;

   head->process = " ";

   head->sysTm = 0.0;

   head->useTm = 0.0;

   head->nxt = NULL;



   displayID();

   displayInfo();



   while(1)

   {

        

        //init just in case

        runmode = 0;   

        redFile = NULL;

        

        //take input from user 

           argNums = takeInpt(commands);



        if( !commands.empty() )

        {

            for(int i=0; i < commands.size(); i++)

            {

                 //vector<char*> com = commands[i];

                 cout<< "Command" << i << " is: ";

                 for(int j=0; j < commands[i].size(); j++)

                 {

                    cout<< commands[i][j];

                 }

   }

        

   //freeList(head);

        

   return 0;



}

This prints out command0 is: command1: (garbage prints here) etc..

Why isn't it echoing back what i typed into the command line for take input?

I am missing something crucial here I think about C/c++

If you could point me in the right direction i would much appreciate. Thanks again for all of your continued help btw.