solverShell.py

#!/usr/bin/python
# -*- coding: utf-8 -*-

import os
from subprocess import Popen, PIPE

def solve_it(input_data):

    # Writes the inputData to a temporay file

    tmp_file_name = 'tmp.data'
    tmp_file = open(tmp_file_name, 'w')
    tmp_file.write(input_data)
    tmp_file.close()

    # NB! dont forget to compile binary, e.g rustc knapsack.rs
    # Runs the command: cat tmp_file_name | ./knapsack
    # and pipes the content of a tmp_file directly into executable
    process = Popen(['cat ' + tmp_file_name + ' | ./knapsack'],
        stdout=PIPE, shell = True, universal_newlines = True
    )
    (stdout, stderr) = process.communicate()

    # removes the temporay file
    os.remove(tmp_file_name)

    return stdout.strip()


import sys

if __name__ == '__main__':
    if len(sys.argv) > 1:
        file_location = sys.argv[1].strip()
        with open(file_location, 'r') as input_data_file:
            input_data = input_data_file.read()
        print(solve_it(input_data))
    else:
        print('This test requires an input file.  Please select one from the data directory. (i.e. python solver.py ./data/ks_4_0)')