Run shell commands in Elixir

Question

I want to execute a program through my Elixir code. What is the method to call a shell command to a given string? Is there anything which isn\'t platform specific?

Answer 1

If I have the following c program in the file a.c:

#include 
#include 

int main(int arc, char** argv)
{

    printf("%s\n",argv[1]);
    printf("%s\n",argv[2]);

    int num1 = atoi(argv[1]);
    int num2 = atoi(argv[2]);

    return num1*num2;
}

and compile the program to the file a:

~/c_programs$ gcc a.c -o a

then I can do:

~/c_programs$ ./a 3 5
3
5

I can get the return value of main() like this:

~/c_programs$ echo $?
15

Similarly, in iex I can do this:

iex(2)> {output, status} = System.cmd("./a", ["3", "5"])
{"3\n5\n", 15}

iex(3)> status
15

The second element of the tuple returned by System.cmd() is the return value of the main() function.