fix(main): exit with code 130 on SIGINT (#615)

main.go

@@ -13,7 +13,26 @@ func main() {
 	ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
 	defer cancel()
 
-	if err := command.Main(ctx, os.Args); err != nil {
+	// intCh receives only SIGINT so we know whether the termination was
+	// caused by Ctrl-C (as opposed to SIGTERM or a command error).  It
+	// must be registered *before* command.Main is called so the signal is
+	// captured even if the command returns very quickly.
+	intCh := make(chan os.Signal, 1)
+	signal.Notify(intCh, os.Interrupt)
+	defer signal.Stop(intCh)
+
+	err := command.Main(ctx, os.Args)
+
+	// Check non-blocking: if the channel already has a value, SIGINT arrived
+	// while the command was running.
+	select {
+	case <-intCh:
+		// SIGINT was the cause; exit 130 per POSIX convention (128 + 2).
+		os.Exit(130)
+	default:
+	}
+
+	if err != nil {
 		os.Exit(1)
 	}
 }

main_test.go

@@ -0,0 +1,67 @@
+package main
+
+import (
+	"os"
+	"os/exec"
+	"syscall"
+	"testing"
+	"time"
+)
+
+// TestSIGINTExitCode verifies that sending SIGINT to s5cmd results in
+// exit code 130 (the POSIX standard: 128 + signal number 2).
+//
+// The test builds the binary, starts it with a long-running command,
+// sends SIGINT after a short delay, and checks the exit code.
+func TestSIGINTExitCode(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping subprocess test in short mode")
+	}
+
+	// Build the binary into a temp dir.
+	tmpDir := t.TempDir()
+	bin := tmpDir + "/s5cmd"
+	if err := exec.Command("go", "build", "-o", bin, ".").Run(); err != nil {
+		t.Fatalf("failed to build s5cmd: %v", err)
+	}
+
+	// Use --no-sign-request so credential lookup is skipped entirely, then
+	// point at a black-hole address.  The binary will block on the TCP dial
+	// for as long as we need.  Setting AWS_DEFAULT_REGION avoids the
+	// region-discovery HTTP call so the binary goes straight to dialling
+	// the black-hole endpoint.
+	cmd := exec.Command(bin,
+		"--no-sign-request",
+		"--endpoint-url", "http://10.255.255.1:19999", // routable but unreachable
+		"--retry-count", "10",
+		"ls", "s3://bucket/",
+	)
+	cmd.Env = append(os.Environ(), "AWS_DEFAULT_REGION=us-east-1")
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+
+	if err := cmd.Start(); err != nil {
+		t.Fatalf("failed to start s5cmd: %v", err)
+	}
+
+	// Give the process time to start and block on the network dial.
+	// Use 3 s to remain reliable even under heavy test-suite parallelism.
+	time.Sleep(3 * time.Second)
+
+	// Send SIGINT.
+	if err := cmd.Process.Signal(syscall.SIGINT); err != nil {
+		t.Fatalf("failed to send SIGINT: %v", err)
+	}
+
+	err := cmd.Wait()
+	exitErr, ok := err.(*exec.ExitError)
+	if !ok {
+		t.Fatalf("expected ExitError after SIGINT, got: %T %v", err, err)
+	}
+
+	got := exitErr.ExitCode()
+	t.Logf("process state: %v", exitErr.ProcessState)
+	if got != 130 {
+		t.Errorf("expected exit code 130 after SIGINT, got %d", got)
+	}
+}