Use SIGTERM to kill child processes on Unix

The cross-platform stdlib API uses SIGKILL, but that doesn't allow
ports and resources to be freed. SIGTERM may fail, but that can be
solved by the user themselves.

Fixes #25 (webserver support)

Cargo.toml

@@ -28,9 +28,10 @@ keywords = [
 [dependencies]
 docopt = "^0.6.78"
 env_logger = "^0.3.2"
-lazy_static = "0.1.15"
+lazy_static = "^0.1.15"
+libc = "^0.2.4"
 log = "^0.3.4"
 notify = "^2.5.4"
 regex = "^0.1.44"
 rustc-serialize = "^0.3.16"
-wait-timeout = "0.1"
+wait-timeout = "^0.1.0"

src/main.rs

@@ -4,6 +4,8 @@ extern crate docopt;
 extern crate env_logger;
 #[macro_use]
 extern crate lazy_static;
+#[cfg(not(windows))]
+extern crate libc;
 #[macro_use]
 extern crate log;
 extern crate notify;

src/schedule.rs

@@ -1,8 +1,10 @@
 use cargo;
 use config;
+#[cfg(not(windows))]
+use libc;
 use notify;
 use std::io;
-use std::process::Command;
+use std::process::{Child, Command};
 use std::sync::{Arc, Mutex};
 use std::sync::mpsc::{channel, Receiver, Sender};
 use std::thread::{self, JoinHandle};
@@ -154,7 +156,7 @@ fn execute_commands(
                 if let Ok(_) = kill.try_recv() {
                     // We got the order to kill the child and terminate
                     debug!("Killing spawned process");
-                    let _ = child.kill();
+                    kill_child(&mut child);
                     abort = true;
                 }
 
@@ -188,3 +190,14 @@ fn execute_commands(
 
     debug!("Command run done");
 }
+
+#[cfg(windows)]
+fn kill_child(child: &mut Child) -> () {
+    let _ = child.kill();
+}
+
+#[cfg(not(windows))]
+fn kill_child(child: &mut Child) -> () {
+    let _ = unsafe { libc::kill(child.id() as i32, libc::SIGTERM) };
+}
+