Merge pull request #417 from schmichael/remove-setenv

Alter subprocess's environment instead of the hosts

internal/common/common.go

@@ -358,3 +358,19 @@ func Pipeline(cmds ...*exec.Cmd) ([]byte, []byte, error) {
 	// Return the pipeline output and the collected standard error
 	return output.Bytes(), stderr.Bytes(), nil
 }
+
+// getSysctrlEnv sets LC_ALL=C in a list of env vars for use when running
+// sysctl commands (see DoSysctrl).
+func getSysctrlEnv(env []string) []string {
+	foundLC := false
+	for i, line := range env {
+		if strings.HasPrefix(line, "LC_ALL") {
+			env[i] = "LC_ALL=C"
+			foundLC = true
+		}
+	}
+	if !foundLC {
+		env = append(env, "LC_ALL=C")
+	}
+	return env
+}

internal/common/common_darwin.go

@@ -12,16 +12,13 @@ import (
 )
 
 func DoSysctrl(mib string) ([]string, error) {
-	err := os.Setenv("LC_ALL", "C")
-	if err != nil {
-		return []string{}, err
-	}
-
 	sysctl, err := exec.LookPath("/usr/sbin/sysctl")
 	if err != nil {
 		return []string{}, err
 	}
-	out, err := exec.Command(sysctl, "-n", mib).Output()
+	cmd := exec.Command(sysctl, "-n", mib)
+	cmd.Env = getSysctrlEnv(os.Environ())
+	out, err := cmd.Output()
 	if err != nil {
 		return []string{}, err
 	}

internal/common/common_freebsd.go

@@ -12,15 +12,13 @@ import (
 )
 
 func DoSysctrl(mib string) ([]string, error) {
-	err := os.Setenv("LC_ALL", "C")
-	if err != nil {
-		return []string{}, err
-	}
 	sysctl, err := exec.LookPath("/sbin/sysctl")
 	if err != nil {
 		return []string{}, err
 	}
-	out, err := exec.Command(sysctl, "-n", mib).Output()
+	cmd := exec.Command(sysctl, "-n", mib)
+	cmd.Env = getSysctrlEnv(os.Environ())
+	out, err := cmd.Output()
 	if err != nil {
 		return []string{}, err
 	}

internal/common/common_linux.go

@@ -9,15 +9,13 @@ import (
 )
 
 func DoSysctrl(mib string) ([]string, error) {
-	err := os.Setenv("LC_ALL", "C")
-	if err != nil {
-		return []string{}, err
-	}
 	sysctl, err := exec.LookPath("/sbin/sysctl")
 	if err != nil {
 		return []string{}, err
 	}
-	out, err := exec.Command(sysctl, "-n", mib).Output()
+	cmd := exec.Command(sysctl, "-n", mib)
+	cmd.Env = getSysctrlEnv(os.Environ())
+	out, err := cmd.Output()
 	if err != nil {
 		return []string{}, err
 	}

internal/common/common_openbsd.go

@@ -12,15 +12,13 @@ import (
 )
 
 func DoSysctrl(mib string) ([]string, error) {
-	err := os.Setenv("LC_ALL", "C")
-	if err != nil {
-		return []string{}, err
-	}
 	sysctl, err := exec.LookPath("/sbin/sysctl")
 	if err != nil {
 		return []string{}, err
 	}
-	out, err := exec.Command(sysctl, "-n", mib).Output()
+	cmd := exec.Command(sysctl, "-n", mib)
+	cmd.Env = getSysctrlEnv(os.Environ())
+	out, err := cmd.Output()
 	if err != nil {
 		return []string{}, err
 	}

internal/common/common_test.go

@@ -2,6 +2,8 @@ package common
 
 import (
 	"fmt"
+	"os"
+	"reflect"
 	"strings"
 	"testing"
 )
@@ -95,3 +97,33 @@ func TestHostEtc(t *testing.T) {
 		t.Errorf("invalid HostEtc, %s", p)
 	}
 }
+
+func TestGetSysctrlEnv(t *testing.T) {
+	// Append case
+	env := getSysctrlEnv([]string{"FOO=bar"})
+	if !reflect.DeepEqual(env, []string{"FOO=bar", "LC_ALL=C"}) {
+		t.Errorf("unexpected append result from getSysctrlEnv: %q", env)
+	}
+
+	// Replace case
+	env = getSysctrlEnv([]string{"FOO=bar", "LC_ALL=en_US.UTF-8"})
+	if !reflect.DeepEqual(env, []string{"FOO=bar", "LC_ALL=C"}) {
+		t.Errorf("unexpected replace result from getSysctrlEnv: %q", env)
+	}
+
+	// Test against real env
+	env = getSysctrlEnv(os.Environ())
+	found := false
+	for _, v := range env {
+		if v == "LC_ALL=C" {
+			found = true
+			continue
+		}
+		if strings.HasPrefix(v, "LC_ALL") {
+			t.Fatalf("unexpected LC_ALL value: %q", v)
+		}
+	}
+	if !found {
+		t.Errorf("unexpected real result from getSysctrlEnv: %q", env)
+	}
+}