Thread: capturing commands at prompt

i am having no luck at all!!

i am trying to prompt the user to enter commands at a prompt and capture what is entered in to a vector of strings

the user can enter any number of whitespaces before or in his input

enter command: (5 spaces) buy (3 spaces) 1000 bushels(2 spaces) corn 3.00

so i am trying to get 'buy' into the vector at pos[0]
'1000' in pos [1]
'bushels' in pos[2]
'corn' pos[3] and so on and so on

i know i can capture the entire line with getline(cin, string);
i know i can get 'buy' by converting string to a stream (iss) and using iss >> cmd;
but the string entered can have any number of words

is there a simpler method which will enable me to do what i want??

Thanks in advance

the >> operators ignores any leading whitespace and stops input at the next encountered whitespace after the first non-whitespace character that was input.

yes i think i get that, but the problem for me is that there is an unknown # of words to be placed in the vector

so i am having trouble using a loop to figure out when to stop

Code:

#include <iostream.h>
#include <stdlib.h>
#include "sstream.h"
#include <string>
#include <vector>

using namespace std;

int main()
{
      string word0, word1, word2, word3, word4, temp;
      vector <string> v;    
      string s("  buy    1000 bushels  corn 300 ");
      cout << s << endl;
      istringstream iss(s);  //this works cause i know # words
      iss >> word0;
      iss >> word1;
      iss >> word2;
      iss >> word3;
      iss >> word4;
      
      cout << word0 << " " << word1<< " " << word2 << " " << word3 << " "
           << word4 << endl; 
      

      //HOW DO I MAKE THIS WORK??    

      string t("  buy    1000 bushels  corn 300 ");
      istringstream jss(t);
      while( **WHAT GOES HERE TO CONTROL LOOP ???? ****)
      {
         jss >> temp;
         v.push_back(temp);
      }
      cout << v[0];

      system("PAUSE");
      return 0;
}

sorry for caps, just wanted to be clear
thanks for your response

Wouldn't while (jss>>temp) work? A stream extraction operation (to my knowledge), is true iff the stream has data to be extracted. I'm away from my compiler, but you could give it a shot.

in your first post you indicate you wanted

vector<string> v;
v[0] = "buy";
v[1] = "1000";
v[2] = "bushels";
v[3] = "corn";
v[4] = "200";

but in you second post I think you want this:

v[0] = "buy 1000 bushels corn 200";
v[1] = "sell 400 tons soybeans 333";
v[2] = "buy 1 porkbelly 0.1";

Which is it?

if the latter, but input can include any number of spaces before or after tokens then I would try the following. It uses char arrays rather than STL strings because I am not as familiar with STL strings or istringstreams:

Code:

char input[256];

cout << "enter order.  Press enter key to terminate the order. ";
cin.getline(input, 256, '\n');

//parse input string removing "extra" spaces
char dummy[256];
int i, j, k = 0;

//ignore any leading spaces in input string
while(input[i] == ' ')
{
  i++;
}

//a single space only between tokens is OK.  Remove others
int spaceCount = 0;
for(j = i ; j < input.length(); j++)
{
  //place each non space char in input into dummy
  if(input[j] != ' ' && count == 0)
    dummy[k++] = input[j];
  else if(input[j] != ' ' && count > 0)
  {
     dummy[k++] = input[j];
     count = 0;
   }

  //put first space between tokens of input string into dummy
  else if (input(j) == ' ' &&  count == 0)
  {
     dummy[k++] = input[j];
     count++;
   }

   //ignore any consecutive spaces between tokens of input string
   else if(input[j] == ' ' && count > 0)
   { 
      count++;
    }
}

//there may be an extra space at end of dummy so look for it and 
//add null chart to end of dummy to make it a string. 
if(dummy[k - 1] == ' ')
{
   dummy[k - 1] = '\0';
}
else
   dummy[k] = '\0';

//now convert dummy to STL string and add that to your vector

it may be that string class contains some "automatic function" to do this, but if so I am not familiar with it.

Thanks for the replies all!

This is what I ended up with:

Code:

 while( true )
      {
         if( jss.eof() ) break;
         jss >> word;
         v.push_back(word);            
      }

code tags end in a /, not \ - Govtcheez

I saw on another post someone said you have to test the validity of the stream. So here I assume it good, and break if bad.

I had tried this once, but did not work in Bloodshed or Visual C++. It does work in Code Warrior and in UNIX (at my university) This is only my second programming class and I was not aware of the big difference the choice of compiler makes. I thought they would all be similar. (MY MISTAKE)

Thanks for the help.