add charset

.gitignore

@@ -1,3 +1,3 @@
-.idea/
+.vscode/
 *.exe
 gohost*

editor/vim.go

@@ -10,7 +10,7 @@ func OpenByVim(filePath string) error {
 	const vim = "vim"
 	const noSwap = "-n"
 	if _, err := exec.LookPath(vim); err != nil {
-		return fmt.Errorf("please install vim before editing file\n")
+		return fmt.Errorf("please install vim before editing file\n %v", err)
 	}
 	cmd := exec.Command(vim, noSwap, filePath)
 	cmd.Stdin = os.Stdin

go.mod

@@ -7,4 +7,5 @@ require (
 	github.com/mattn/go-runewidth v0.0.13 // indirect
 	github.com/olekukonko/tablewriter v0.0.5
 	github.com/spf13/cobra v1.2.1
+	golang.org/x/text v0.3.7
 )

go.sum

@@ -393,6 +393,8 @@ golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.4/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.5/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/text v0.3.7 h1:olpwvP2KacW1ZWvsR7uQhoyTYvKAupfQrRGBFM352Gk=
+golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
 golang.org/x/time v0.0.0-20181108054448-85acf8d2951c/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/time v0.0.0-20190308202827-9d24e82272b4/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/time v0.0.0-20191024005414-555d28b269f0/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=

host/host.go

@@ -5,10 +5,11 @@
 package host
 
 import (
-	"github.com/ingbyr/gohost/conf"
-	"github.com/ingbyr/gohost/util"
 	"path"
 	"strings"
+
+	"github.com/ingbyr/gohost/conf"
+	"github.com/ingbyr/gohost/util"
 )
 
 type Host struct {
@@ -52,8 +53,9 @@ func NewHostByFileName(fileName string) *Host {
 }
 
 func NewHostByNameGroups(hostName string, groups []string) *Host {
+
 	// use host name as group if no specified groups
-	if len(groups) == 0 {
+	if len(groups) == 0 && hostName != conf.TmpCombinedHost {
 		groups = append(groups, hostName)
 	} else {
 		// sort and unique the groups
@@ -77,4 +79,4 @@ func HostsToStr(hosts []*Host) string {
 		hsb.WriteString(", ")
 	}
 	return hsb.String()[:hsb.Len()-2]
-}
+}

host/manager.go

@@ -8,14 +8,16 @@ import (
 	"bufio"
 	"bytes"
 	"fmt"
+	"os"
+	"sort"
+	"strings"
+
 	"github.com/ingbyr/gohost/conf"
 	"github.com/ingbyr/gohost/display"
 	"github.com/ingbyr/gohost/editor"
 	"github.com/ingbyr/gohost/myfs"
 	"github.com/ingbyr/gohost/util"
-	"io/ioutil"
-	"sort"
-	"strings"
+	"golang.org/x/text/transform"
 )
 
 type manager struct {
@@ -218,19 +220,19 @@ func (m *manager) AddGroup(hostName string, groups []string) {
 
 func (m *manager) CreateNewHost(name string, groups []string, edit bool) {
 	if name == m.baseHost.Name {
-		display.ErrExit(fmt.Errorf("host file '%s' already exists\n", name))
+		display.ErrExit(fmt.Errorf("host file '%s' already exists", name))
 	}
 	if _, exist := m.hosts[name]; exist {
-		display.ErrExit(fmt.Errorf("host file '%s' already exists\n", name))
+		display.ErrExit(fmt.Errorf("host file '%s' already exists", name))
 	}
 	host := NewHostByNameGroups(name, groups)
 	if edit {
 		if err := editor.OpenByVim(host.FilePath); err != nil {
-			display.ErrExit(fmt.Errorf("failed to create file '%s'\n", host.FilePath))
+			display.ErrExit(fmt.Errorf("failed to create file '%s'\n%v", host.FilePath, err))
 		}
 	} else {
 		if err := m.fs.WriteFile(host.FilePath, []byte(""), myfs.Perm644); err != nil {
-			display.ErrExit(fmt.Errorf("can not create %s file\n", host.FilePath))
+			display.ErrExit(fmt.Errorf("can not create %s file\n%v", host.FilePath, err))
 		}
 	}
 }
@@ -255,7 +257,7 @@ func (m *manager) ChangeHostName(hostName string, newHostName string) {
 		display.ErrExit(fmt.Errorf("can not change base host file name"))
 	}
 	if _, exist := m.host(newHostName); exist {
-		display.ErrExit(fmt.Errorf("host '%s' has been existed\n", newHostName))
+		display.ErrExit(fmt.Errorf("host '%s' has been existed", newHostName))
 	}
 	h := m.mustHost(hostName)
 	newHost := NewHostByNameGroups(newHostName, h.Groups)
@@ -304,13 +306,21 @@ func (m *manager) ApplyGroup(group string, simulate bool) {
 		return
 	}
 
-	// write to tmp file
+	// write to temporary combined host file
 	combinedHost := NewHostByNameGroups(conf.TmpCombinedHost, nil)
-	if err := ioutil.WriteFile(combinedHost.FilePath, combinedHostContent, 0664); err != nil {
+	combinedHostFile, err := os.Create(combinedHost.FilePath)
+	if err != nil {
+		display.ErrExit(err)
+	}
+	combinedHostFileWriter := transform.NewWriter(combinedHostFile, SysHostCharset.NewEncoder())
+	_, err = combinedHostFileWriter.Write(combinedHostContent)
+	if err != nil {
 		display.ErrExit(err)
 	}
+	combinedHostFile.Close()
+	combinedHostFileWriter.Close()
 
-	// replace system host
+	// replace system host with temporary combined host file
 	if err := m.fs.Rename(combinedHost.FilePath, SysHost); err != nil {
 		display.ErrExit(err)
 	}
@@ -351,7 +361,7 @@ func (m *manager) host(hostName string) (*Host, bool) {
 func (m *manager) mustHost(hostName string) *Host {
 	host, exist := m.host(hostName)
 	if !exist {
-		display.ErrExit(fmt.Errorf("host file '%s' is not existed\n", hostName))
+		display.ErrExit(fmt.Errorf("host file '%s' is not existed", hostName))
 	}
 	return host
 }
@@ -364,7 +374,7 @@ func (m *manager) group(groupName string) ([]*Host, bool) {
 func (m *manager) mustGroup(groupName string) []*Host {
 	group, exist := m.group(groupName)
 	if !exist {
-		display.ErrExit(fmt.Errorf("group '%s' is not existed\n", groupName))
+		display.ErrExit(fmt.Errorf("group '%s' is not existed", groupName))
 	}
 	return group
 }

host/unix.go

@@ -1,12 +1,21 @@
-//+build linux darwin
+//go:build linux || darwin
+// +build linux darwin
 
 /*
  @Author: ingbyr
 */
 
 package host
 
+import (
+	"golang.org/x/text/encoding/unicode"
+)
+
 const (
 	SysHost = "/etc/hosts"
 	NewLine = "\n"
 )
+
+var (
+	SysHostCharset = unicode.UTF8
+)

host/windows.go

@@ -1,11 +1,19 @@
-//+build windows
+//go:build windows
+// +build windows
 
 /*
  @Author: ingbyr
 */
 package host
 
+import "golang.org/x/text/encoding/charmap"
+
 const (
-	sysHost = "C:\\Windows\\System32\\drivers\\etc\\hosts"
+	SysHost = "C:\\Windows\\System32\\drivers\\etc\\hosts"
 	NewLine = "\r\n"
 )
+
+var (
+	// see https://stackoverflow.com/questions/701882/what-is-ansi-format/702023#702023
+	SysHostCharset = charmap.ISO8859_1
+)