From 0d6d1f1cbaf890a543d9dbce0cf9647be9fefbb0 Mon Sep 17 00:00:00 2001
From: Hugo Frappier <hfrappier@gmail.com>
Date: Mon, 14 May 2018 12:22:00 -0400
Subject: [PATCH] Add basic windows support

---
 cmd.go         |  8 +++-----
 cmd_darwin.go  | 20 ++++++++++++++++++++
 cmd_linux.go   | 20 ++++++++++++++++++++
 cmd_windows.go | 20 ++++++++++++++++++++
 4 files changed, 63 insertions(+), 5 deletions(-)
 create mode 100644 cmd_darwin.go
 create mode 100644 cmd_linux.go
 create mode 100644 cmd_windows.go

diff --git a/cmd.go b/cmd.go
index 40a11df..400d40d 100644
--- a/cmd.go
+++ b/cmd.go
@@ -201,7 +201,7 @@ func (c *Cmd) Stop() error {
 	// Signal the process group (-pid), not just the process, so that the process
 	// and all its children are signaled. Else, child procs can keep running and
 	// keep the stdout/stderr fd open and cause cmd.Wait to hang.
-	return syscall.Kill(-c.status.PID, syscall.SIGTERM)
+	return terminateProcess(c.status.PID)
 }
 
 // Status returns the Status of the command at any time. It is safe to call
@@ -273,10 +273,8 @@ func (c *Cmd) run() {
 	// //////////////////////////////////////////////////////////////////////
 	cmd := exec.Command(c.Name, c.Args...)
 
-	// Set process group ID so the cmd and all its children become a new
-	// process group. This allows Stop to SIGTERM the cmd's process group
-	// without killing this process (i.e. this code here).
-	cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
+	// Platform-specific SysProcAttr management
+	setProcessGroupID(cmd)
 
 	// Write stdout and stderr to buffers that are safe to read while writing
 	// and don't cause a race condition.
diff --git a/cmd_darwin.go b/cmd_darwin.go
new file mode 100644
index 0000000..6d6a960
--- /dev/null
+++ b/cmd_darwin.go
@@ -0,0 +1,20 @@
+package cmd
+
+import (
+	"os/exec"
+	"syscall"
+)
+
+func terminateProcess(pid int) error {
+	// Signal the process group (-pid), not just the process, so that the process
+	// and all its children are signaled. Else, child procs can keep running and
+	// keep the stdout/stderr fd open and cause cmd.Wait to hang.
+	return syscall.Kill(-pid, syscall.SIGTERM)
+}
+
+func setProcessGroupID(cmd *exec.Cmd) {
+	// Set process group ID so the cmd and all its children become a new
+	// process group. This allows Stop to SIGTERM the cmd's process group
+	// without killing this process (i.e. this code here).
+	cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
+}
diff --git a/cmd_linux.go b/cmd_linux.go
new file mode 100644
index 0000000..6d6a960
--- /dev/null
+++ b/cmd_linux.go
@@ -0,0 +1,20 @@
+package cmd
+
+import (
+	"os/exec"
+	"syscall"
+)
+
+func terminateProcess(pid int) error {
+	// Signal the process group (-pid), not just the process, so that the process
+	// and all its children are signaled. Else, child procs can keep running and
+	// keep the stdout/stderr fd open and cause cmd.Wait to hang.
+	return syscall.Kill(-pid, syscall.SIGTERM)
+}
+
+func setProcessGroupID(cmd *exec.Cmd) {
+	// Set process group ID so the cmd and all its children become a new
+	// process group. This allows Stop to SIGTERM the cmd's process group
+	// without killing this process (i.e. this code here).
+	cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
+}
diff --git a/cmd_windows.go b/cmd_windows.go
new file mode 100644
index 0000000..63ef84f
--- /dev/null
+++ b/cmd_windows.go
@@ -0,0 +1,20 @@
+package cmd
+
+import (
+	"fmt"
+	"os/exec"
+	"syscall"
+)
+
+// Stop stops the command by sending its process group a SIGTERM signal.
+// Stop is idempotent. An error should only be returned in the rare case that
+// Stop is called immediately after the command ends but before Start can
+// update its internal state.
+func terminateProcess(pid int) error {
+	kill := exec.Command("TASKKILL", "/T", "/F", "/PID", fmt.Sprintf("%d", pid))
+	return kill.Run()
+}
+
+func setProcessGroupID(cmd *exec.Cmd) {
+	cmd.SysProcAttr = &syscall.SysProcAttr{}
+}