Question

1. Write a complete C++ program named “CheckAmount” that accepts command line arguments. It checks whether there is a command line argument of “-amount” followed by an amount number. It will print out that number amount. For all other cases, it will print out -1. For example, if you run this program with correct arguments as follows, it will print out 1.99, 0.75 and 1.1 respectively CheckAmount -amount 1.99 CheckAmount -help -amount 0.75 CheckAmount -help -check -amount 1.1 -verbose And if you run the program with invalid arguments, it will print -1 in all cases CheckAmount -amount -verbose CheckAmount -help -amount CheckAmount -amount CheckAmount amount 1.0 CheckAmount

Answer 1

Here is the c++ code:

#include <iostream>

#include <ctype.h> //for ifdigit() function

using namespace std;

//function to check if a string is floating point number or not

//it should have 0 or 1 dots and rest all digits

bool check(string s2)

{

   int dots = 0;

   for (int i = 0; i < s2.size(); ++i)

   

       if (s2[i] == '.')

           dots++;

       else if (!isdigit(s2[i]))

           return false;

       else

           continue;

   

   if (dots < 2)

       return true;

   return false;

}

int main(int argc, char **argv)

{

   for (int i = 1; i < argc; ++i)

   

       string s(argv[i]);

       if (s == "-amount")//if a command line argument is -amount

       

           for (int j = i + 1; j < argc; ++j)//check the following arguments for a float number

           

               string s2 = argv[j];

               if (check(s2))

               

                   cout << s2 << endl;

                   return 0;

               

           

           break;

       

   

   cout << "-1" << endl;

   return 0;

}

Sample IO:

1: bash x TERMINAL [unseen@pc]07:16 am_$ ~/prog/CPP g++ CheckAmount.cpp -o CheckAmount [unseen@pc]07:17 am_$ ~/prog/CPP ./CheckAmount -amount 1.99 -> -> 1.99 [unseen@pc]07:17 am_$ ~/prog/CPP ./CheckAmount -help -amount 0.75 -> 0.75 [unseen@pc]07:17 am_$ ~/prog/CPP -> ./CheckAmount -help -check -amount 1.1 -verbose 1.1 [unseen@pc]07:17 am_$ ~/prog/CPP ./CheckAmount -amount -verbose -> -1 [unseen@pc]07:17 am_$ ~/prog/CPP ./CheckAmount -help -amount -> -1 [unseen@pc]07:17 am_$ ~/prog/CPP ./CheckAmount -amount - 1 [unseen@pc]07:18 am_$ ~/prog/CPP -> ./CheckAmount amount 1.0 -1 [unseen@pc]07:18 am_$ ~/prog/CPP > ./CheckAmount -1 [unseen@pc]07:18 am_$ ~/prog/CPP