Launch child processes in new process group

Cargo.lock

@@ -1,10 +1,11 @@
 [root]
 name = "watchexec"
-version = "1.1.0"
+version = "1.1.1"
 dependencies = [
  "clap 2.14.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "env_logger 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "glob 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "notify 2.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]

Cargo.toml

@@ -15,6 +15,7 @@ lto = true
 
 [dependencies]
 glob = "0.2.11"
+libc = "0.2.16"
 log = "0.3.6"
 notify = "2.6.3"
 

src/main.rs

@@ -1,6 +1,9 @@
+#![feature(process_exec)]
+
 #[macro_use]
 extern crate clap;
 extern crate env_logger;
+extern crate libc;
 #[macro_use]
 extern crate log;
 extern crate notify;

src/runner.rs

@@ -1,3 +1,4 @@
+use libc;
 use std::process::{Child, Command};
 
 pub struct Runner {
@@ -11,7 +12,7 @@ impl Runner {
         Runner {
             process: None,
             restart: restart,
-            cls: clear,
+            cls: clear
         }
     }
 
@@ -25,6 +26,22 @@ impl Runner {
         let _ = Command::new("clear").status();
     }
 
+    #[cfg(target_family = "windows")]
+    fn kill(child: &mut Child) {
+        let _ = child.kill();
+    }
+
+    #[cfg(target_family = "unix")]
+    fn kill(child: &mut Child) {
+        extern {
+            fn killpg(pgrp: libc::pid_t, sig: libc::c_int) -> libc::c_int;
+        }
+
+        unsafe {
+            killpg(child.id() as i32, libc::SIGTERM);
+        }
+    }
+
     #[cfg(target_family = "windows")]
     fn invoke(&self, cmd: &str, updated_paths: Vec<&str>) -> Option<Child> {
         let mut command = Command::new("cmd.exe");
@@ -39,6 +56,8 @@ impl Runner {
 
     #[cfg(target_family = "unix")]
     fn invoke(&self, cmd: &str, updated_paths: Vec<&str>) -> Option<Child> {
+        use std::os::unix::process::CommandExt;
+
         let mut command = Command::new("sh");
         command.arg("-c").arg(cmd);
 
@@ -46,18 +65,21 @@ impl Runner {
             command.env("WATCHEXEC_UPDATED_PATH", updated_paths[0]);
         }
 
-        command.spawn().ok()
+        command
+            .before_exec(|| unsafe { libc::setpgid(0, 0); Ok(()) })
+            .spawn()
+            .ok()
     }
 
     pub fn run_command(&mut self, cmd: &str, updated_paths: Vec<&str>) {
         if let Some(ref mut child) = self.process {
             if self.restart {
                 debug!("Killing child process (pid: {})", child.id());
-                let _ = child.kill();
+                Runner::kill(child);
             }
 
             debug!("Waiting for child process (pid: {})", child.id());
-            let _ = child.wait();
+            Runner::wait(child);
         }
 
         if self.cls {
@@ -68,4 +90,19 @@ impl Runner {
 
         self.process = self.invoke(cmd, updated_paths);
     }
+
+    #[cfg(target_family = "windows")]
+    fn wait(child: &mut Child) {
+        let _ = child.wait();
+    }
+
+    #[cfg(target_family = "unix")]
+    fn wait(child: &mut Child) {
+        unsafe {
+            let pid = child.id() as i32;
+            let status: Box<i32> = Box::new(0);
+            libc::waitpid(-pid, Box::into_raw(status), 0);
+        }
+    }
+
 }