Use os:cmd instead of Erlang ports

[gootik]

os:cmd handles many edge cases and in general is better.

[gootik]

Would also fix #16

[paulo-ferraz-oliveira]

I don't think the current implementation supports it, but I'd like to see commands expressed so:

{check, ["make xref", "make dialyzer"]} % list of strings

and also

{test, "make test"} % single string

in which case, a "quickfix" for #16 would be to use the new syntax (list of string).

[gootik]

@paulo-ferraz-oliveira I like the first suggestion. but I still think we should change to os:cmd.

[paulo-ferraz-oliveira]

I still think we should change to os:cmd.

Oh, I was intending on using it 😄. When I wrote "I don't think the current implementation supports it" I was referring to what I was going to expose below it.

So:

1. use os:cmd,
2. implement a command syntax like:

{check, ["make xref", "make dialyzer"]} % list of strings

while not breaking backward compatibility.

[gootik]

yeah that's perfect

[paulo-ferraz-oliveira]

With the previous implementation you could always recover the return code from the command, which won't be possible with os:cmd it seems.

Is this acceptable?

[paulo-ferraz-oliveira]

Reading ref.: http://www.arv.io/articles/calling-shell-from-erlang.

[paulo-ferraz-oliveira]

I ended up not implementing this syntax

{check, ["make xref", "make dialyzer"]} % list of strings

as several questions arose that would make its UX difficult.
If its asked for, in the future, we could consider it.