c++ argv argument not parsing * from command line -

i have issue * character in command line input.

the commands these:

2.exe input.txt output.txt + 2 2.exe input.txt output.txt - 2 2.exe input.txt output.txt * 2 

it works perfectly, except last one. somehow not * character command line. if put '*' works, not idea.

i searched web, , closest got globals being mentioned somewhere, not sure how it. here code

#include <iostream> #include <fstream> #include <cstdlib>  using namespace std;  int main(int argc, char * argv[]) {      ifstream infile(argv[1]);     ofstream outfile(argv[2]);        if (infile.is_open() && infile.good()) {         int num;         int sum = 0;         string arg = string(argv[3]);         int val = atoi(argv[4]);           while(infile >> num)         {          if(arg == "+") sum = num + val;         else if(arg == "-") sum = num - val;         else sum = num * val;            cout << "sum: " << num << endl;         cout << "sum: " << sum << endl;         outfile << sum << " ";         }          outfile.close();       } else {         cout << "faila ne se otvarq";     }     return 0; } 

because of shell expansion, * expanded shell files in current directory, should use either

2.exe input.txt output.txt '*' 2 

or

2.exe input.txt output.txt \* 2