How to pass in command line arguments when using i

问题:

I'm using the ideone online interpreter (http://ideone.com/) to test some C++ and Python programs. How do I specify the command line arguments instead of using the STDIN input?

回答1:

Looks like you can't, but a quick hack should do the trick:

static char * const ARGV[] = { "myprog", "hello", "world", NULL };

int main(int argc, char * argv[])
{
    argc = 3;
    argv = ARGV;

    // ...
}

Or convert the standard input into args:

#include <vector>
#include <string>
#include <iterator>
#include <iostream>

std::vector<char *> fabricate(std::vector<std::string> & v)
{
    std::vector<char *> res(v.size() + 1, NULL);
    for (std::size_t i = 0; i != v.size(); ++i) { res[i] = &v[i][0]; }
    return res;
}

std::vector<std::string> args_vector((std::istream_iterator<std::string>(std::cin)), std::istream_iterator<std::string>());

std::vector<char *> argv_vector = fabricate(args_vector);


int main(int argc, char * argv[])
{
    argc = args_vector.size();
    argv = argv_vector.data();

    // ...
}

回答2:

In python you can hardcode like this:

import sys

print sys.argv
sys.argv[1:] = ["test1", "test2"]
print sys.argv

This will output:

['prog.py']
['prog.py', 'test1', 'test2']

To read from stdin:

import sys
import shlex

print sys.argv
sys.argv[1:] = shlex.split(None)
print sys.argv

回答3:

Just initialize to simulate the command line arguments

static char *argv[] = {"program_name", "1st argument", "2nd argument", NULL};
static int argc = 3;
int main() {

}