#include<iostream>      //Preprocessor commands
#include<string>
#include<cstdlib>
using namespace std;    //Using namespace library

int input_val();        //Function prototype

int main()              //Driver function header
{
    char ch;

    cout<<"                               "<<input_val()<<" is a valid integer entry."<<endl<<endl;

    cout<<"Enter 'e' to exit... ";
    cin>>ch;

    return 0;
}

int input_val()
{
    string text;
    int n = 99, i, x; //Defining n, i, and x

    while (n != 0) //As long as n doesn't equal 0, do the following...
    {
        try
        {
            //Obtain user input
            cout<<"Please enter an integer ('e' to exit): ";
            getline(cin,text);


            if (text == "e") throw 3;   //If user inputs the letter e, exit the program

            if (text.length() == 0) throw 1; //Making sure it has a length greater then 0

			if (text[0] == '+');

				for (i = 0; i <text.length(); i++) if (!isdigit(text.at(i))) throw 2; //Looking for more digits or a decimal point

			atoi(text.c_str());

			if (text > "255") throw 4; //Making sure the number is not greater then 255

            if (text < "0") throw 5; //Making sure the user didn't input a negative

            //If all the tests go well, move on with the program
            n = 0;
        }
        catch (int e)
        {
            if (e == 1) cout<<"\n          No input was entered!"<<endl<<"          Try again... "; //Telling the user what went wrong
            if (e == 2) cout<<"\n          You either entered a letter or a symbol that is not a number."<<endl<<"          Try again... ";
            if (e == 3) exit(0);
            if (e == 4) cout<<"\n          You put in a number greater than 255."<<endl<<"          Try again... ";
            if (e == 5) cout<<"\n          You put in a negative number! No negatives!"<<endl<<"          Try again... ";


            n = 99; //Resetting the setinel so the while loop can run again
        }
    }
    //Converting C string to an integer with atoi
    return atoi(text.c_str());
}