I'm currently trying to automate the testing of a C++ program which takes input from the terminal and outputs the result onto the terminal. For example my C++ file would do something like below:
#include <iostream>
int main() {
int a, b;
std::cin >> a >> b;
std::cout << a + b;
}
And my Python file used for testing would be like:
as = [1, 2, 3, 4, 5]
bs = [2, 3, 1, 4, 5]
results = []
for i in range(5):
# input a[i] and b[i] into the C++ program
# append answer from C++ program into results
Although it is possible to input and output from C++ through file I/O, I'd rather leave the C++ program untouched.
What can I do instead of the commented out lines in the Python program?
You could use subprocess.Popen
. Sample code:
#include <iostream>
int sum(int a, int b) {
return a + b;
}
int main ()
{
int a, b;
std::cin >> a >> b;
std::cout << sum(a, b) << std::endl;
}
from subprocess import Popen, PIPE
program_path = "/home/user/sum_prog"
p = Popen([program_path], stdout=PIPE, stdin=PIPE)
p.stdin.write(b"1\n")
p.stdin.write(b"2\n")
p.stdin.flush()
result = p.stdout.readline().strip()
assert result == b"3"