Heres a snippet of my code:

int main();
{
     string cmd1;
     int cmd2;

     cout << "Command: " << flush;
     cin >> cmd1;

     if (cmd1 == "playlist")
     {
	     cin >> cmd2;
	     if (cmd2==XXXXXX)
	     {
		     cout << "Illegal command: " << cmd1 << endl;
	     }
	     else
	     cmdPlaylist(cmd2);
     }

return 0;
}

If input is playlist 6

then action would be run cmdPlaylist(6);

If input is playlist

then action would cout << "Illegal Command: " << cmd1 << endl;

My question is:

How do I get my program to print

cout << "Illegal Command: " << cmd1 << endl;

if there is no cmd2.


Is there some function I can use that states

if cmd2!=an integer
or
if cmd2!=no input/invalid

then cout << "Illegal Command: " << cmd1 << endl;

Oddly enough, most of the problems with stream input are solved the same way: read an entire line into a string and then parse that line for validity:

#include <iostream>
#include <sstream>
#include <string>

int main()
{
    std::string line;

    std::cout<<"> ";

    if ( getline ( std::cin, line ) ) {
        std::istringstream in ( line );
        std::string command;
        int argument;

        if ( in>> command >> argument )
            std::cout<<"Valid\n";
        else
            std::cout<<"Invalid\n";
    }
}

1. here's this forum announcement: http://www.daniweb.com/forums/announcement8-3.html
[code=cplusplus] source

[/code]
2. See an example of these cmds parsing:

// don't forget to include <sstream>
typedef istringstream::pos_type Pos;
// cmd arg parsing sample only:
void cmdGet()
{
    string line, cmd, arg;
    bool intarg = false;
    int  iarg;
    cout << "Type instruction: "; // no need in flush
    if (getline(cin,line)) {
        istringstream is(line); // parse line
        if (is >> cmd) {    // get 1st token
            Pos pos = is.tellg();//save position
            if (is >> arg) {    // has arg
                is.seekg(pos);  // read again
                if (is >> iarg) // try to get int
                    intarg = true;
                else
                    intarg = false; // not-a-number
            } else { // no arg
                arg.clear(); // arg.empty() == true
            }
            // Process cmd & arg, for example:
            cout << cmd;
            if (!arg.empty()) { // has arg
                cout << ' ' << arg;
                if (intarg)
                    cout << " (integer)";
            }
            cout << endl;
        } else { // no cmd at all
            cout << "Try again...\n";
        }
    } else { // cin closed
        return; // ctrl-z on Windows, for example
    }
}

Try this. Adopt it (it's freeware in the public domain ;)...

Lets say I have an input

playlist 6

Then I need to extract 6 from the string and store it as an integer how would I do it?

I know

springstream in(6)

then in become 6

would convert the 6 itself

but if I apply

springstream in(playlist 6)

then in becomes 0.

Did you even bother to read my example? You butchered it beyond comprehension despite the fact that it already does what you're currently asking for. :icon_rolleyes:

[edit]
By the way, I'm merging this into the original thread so you don't confuse the bejeezus out of everyone.
[/edit]

Did you even bother to read my example? You butchered it beyond comprehension despite the fact that it already does what you're currently asking for. :icon_rolleyes:

[edit]
By the way, I'm merging this into the original thread so you don't confuse the bejeezus out of everyone.
[/edit]

Sorry, its not that I tried to butcher. It's just I don't really understand what you've given me.

//Edit
Now I do, sorry once again... Don't kill me! I'm sorry!

Most importantly thanks alot!

>Don't kill me! I'm sorry!
Rawr! ;)

hehe XD

I've got another question :P

I have 3 input commands:

info
playlist n
quit

and I'm using an if statement to identify command = input.

e.g
cout << "Command: " << flush;
getline(cin, line);

if (cmd == quit)
return 0;
else if (cmd == info)
cmdInfo(cmd);
else if (cmd == playlist n)
cout << "This is tripping me up" << endl;
else
cout << "Illegal Command: " << cmd << endl;

The problem with Playlist n is n could be any number.

So what I want to know is if there is any command/function that allows me to only read the first part of the string?

I tried using getline(cin, line, ' ');

However, it put the program into an infinite loop.

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