From e58f376e4c4e6d31fd9158582222dfff1c90b3df Mon Sep 17 00:00:00 2001
From: Virgil <virgil@lethean.io>
Date: Fri, 3 Apr 2026 23:53:19 +0000
Subject: [PATCH] feat(process): signal process groups

---
 process.go      |  8 ++++++++
 process_test.go | 22 ++++++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/process.go b/process.go
index 9a2ad0b..80f43b0 100644
--- a/process.go
+++ b/process.go
@@ -188,6 +188,14 @@ func (p *Process) Signal(sig os.Signal) error {
 		return nil
 	}
 
+	if p.killGroup {
+		sysSig, ok := sig.(syscall.Signal)
+		if !ok {
+			return p.cmd.Process.Signal(sig)
+		}
+		return syscall.Kill(-p.cmd.Process.Pid, sysSig)
+	}
+
 	return p.cmd.Process.Signal(sig)
 }
 
diff --git a/process_test.go b/process_test.go
index 302bc9e..0dd9ebe 100644
--- a/process_test.go
+++ b/process_test.go
@@ -225,6 +225,28 @@ func TestProcess_Signal(t *testing.T) {
 		err = proc.Signal(os.Interrupt)
 		assert.ErrorIs(t, err, ErrProcessNotRunning)
 	})
+
+	t.Run("signals process group when kill group is enabled", func(t *testing.T) {
+		svc, _ := newTestService(t)
+
+		proc, err := svc.StartWithOptions(context.Background(), RunOptions{
+			Command:   "sh",
+			Args:      []string{"-c", "trap '' INT; sh -c 'trap - INT; sleep 60' & wait"},
+			Detach:    true,
+			KillGroup: true,
+		})
+		require.NoError(t, err)
+
+		err = proc.Signal(os.Interrupt)
+		assert.NoError(t, err)
+
+		select {
+		case <-proc.Done():
+			// Good - the whole process group responded to the signal.
+		case <-time.After(5 * time.Second):
+			t.Fatal("process group should have been terminated by signal")
+		}
+	})
 }
 
 func TestProcess_CloseStdin(t *testing.T) {