Merge pull request #26 from goodhosts/win-hosts

fix windows hosts per line problem

.github/workflows/ci.yml

@@ -12,14 +12,7 @@ jobs:
         id: go
       - name: Checkout
         uses: actions/checkout@v2
-      - name: Run goimports
-        run: |
-          go install golang.org/x/tools/cmd/goimports@latest
-          output="$($(go env GOPATH)/bin/goimports -l .)"
-          test -z $output && exit 0
-          $(go env GOPATH)/bin/goimports -d .
-          exit 1
-      - name: Test
+      - name: Validate and Test
         env:
           GOROOT: ""
         run: |

go.mod

@@ -2,4 +2,14 @@ module github.com/goodhosts/hostsfile
 
 go 1.17
 
-require github.com/dimchansky/utfbom v1.1.1
+require (
+	github.com/asaskevich/govalidator v0.0.0-20210307081110-f21760c49a8d
+	github.com/dimchansky/utfbom v1.1.1
+	github.com/stretchr/testify v1.7.0
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.0 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c // indirect
+)

go.sum

@@ -1,2 +1,15 @@
+github.com/asaskevich/govalidator v0.0.0-20210307081110-f21760c49a8d h1:Byv0BzEl3/e6D5CLfI0j/7hiIEtvGVFPCZ7Ei2oq8iQ=
+github.com/asaskevich/govalidator v0.0.0-20210307081110-f21760c49a8d/go.mod h1:WaHUgvxTVq04UNunO+XhnAqY/wQc+bxr74GqbsZ/Jqw=
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/dimchansky/utfbom v1.1.1 h1:vV6w1AhK4VMnhBno/TPVCoK9U/LP0PkLCS9tbxHdi/U=
 github.com/dimchansky/utfbom v1.1.1/go.mod h1:SxdoEBH5qIqFocHMyGOXVAybYJdr71b1Q/j0mACtrfE=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

hosts.go

@@ -9,6 +9,7 @@ import (
 	"path/filepath"
 	"sort"
 
+	"github.com/asaskevich/govalidator"
 	"github.com/dimchansky/utfbom"
 )
 
@@ -17,7 +18,7 @@ type Hosts struct {
 	Lines []HostsLine
 }
 
-// Return a new instance of ``Hosts`` using the default hosts file path.
+// NewHosts return a new instance of ``Hosts`` using the default hosts file path.
 func NewHosts() (Hosts, error) {
 	osHostsFilePath := os.ExpandEnv(filepath.FromSlash(HostsFilePath))
 
@@ -28,7 +29,7 @@ func NewHosts() (Hosts, error) {
 	return NewCustomHosts(osHostsFilePath)
 }
 
-// Return a new instance of ``Hosts`` using a custom hosts file path.
+// NewCustomHosts return a new instance of ``Hosts`` using a custom hosts file path.
 func NewCustomHosts(osHostsFilePath string) (Hosts, error) {
 	hosts := Hosts{
 		Path: osHostsFilePath,
@@ -41,7 +42,7 @@ func NewCustomHosts(osHostsFilePath string) (Hosts, error) {
 	return hosts, nil
 }
 
-// Return ```true``` if hosts file is writable.
+// IsWritable return ```true``` if hosts file is writable.
 func (h *Hosts) IsWritable() bool {
 	file, err := os.OpenFile(h.Path, os.O_WRONLY, 0660)
 	if err != nil {
@@ -75,6 +76,7 @@ func (h *Hosts) Load() error {
 
 // Flush any changes made to hosts file.
 func (h Hosts) Flush() error {
+	h.preFlushClean()
 	file, err := os.Create(h.Path)
 	if err != nil {
 		return err
@@ -116,6 +118,9 @@ func (h *Hosts) Add(ip string, hosts ...string) error {
 		// add new hosts to the correct position for the ip
 		hostsCopy := h.Lines[position].Hosts
 		for _, addHost := range hosts {
+			if !govalidator.IsDNSName(addHost) {
+				return fmt.Errorf("hostname is not a valid dns name: %s", addHost)
+			}
 			if itemInSlice(addHost, hostsCopy) {
 				continue // host exists for ip already
 			}
@@ -129,7 +134,7 @@ func (h *Hosts) Add(ip string, hosts ...string) error {
 	return nil
 }
 
-// merge dupelicate ips and hosts per ip
+// Clean merge duplicate ips and hosts per ip
 func (h *Hosts) Clean() {
 	h.RemoveDuplicateIps()
 	h.RemoveDuplicateHosts()
@@ -138,12 +143,12 @@ func (h *Hosts) Clean() {
 	h.HostsPerLine(HostsPerLine)
 }
 
-// Return a bool if ip/host combo in hosts file.
+// Has return a bool if ip/host combo in hosts file.
 func (h Hosts) Has(ip string, host string) bool {
 	return h.getHostPosition(ip, host) != -1
 }
 
-// Return a bool if hostname in hosts file.
+// HasHostname return a bool if hostname in hosts file.
 func (h Hosts) HasHostname(host string) bool {
 	return h.getHostnamePosition(host) != -1
 }
@@ -189,7 +194,7 @@ func (h *Hosts) Remove(ip string, hosts ...string) error {
 	return nil
 }
 
-// Remove  entries by hostname from the hosts file.
+// RemoveByHostname remove entries by hostname from the hosts file.
 func (h *Hosts) RemoveByHostname(host string) error {
 	newLines := []HostsLine{}
 	for _, line := range h.Lines {
@@ -243,7 +248,7 @@ func (h *Hosts) SortHosts() {
 	}
 }
 
-// convert to net.IP and byte.Compare
+// SortByIp convert to net.IP and byte.Compare
 func (h *Hosts) SortByIp() {
 	sortedIps := make([]net.IP, 0, len(h.Lines))
 	for _, l := range h.Lines {
@@ -265,6 +270,8 @@ func (h *Hosts) SortByIp() {
 }
 
 func (h *Hosts) HostsPerLine(count int) {
+	// restacks everything into 1 ip again so we can do the split, do this even if count is -1 so it can reset the slice
+	h.RemoveDuplicateIps()
 	if count <= 0 {
 		return
 	}
@@ -281,6 +288,7 @@ func (h *Hosts) HostsPerLine(count int) {
 			if end > i+count {
 				end = i + count
 			}
+
 			lineCopy.Hosts = line.Hosts[i:end]
 			lineCopy.Raw = lineCopy.ToRaw()
 			newLines = append(newLines, lineCopy)
@@ -365,3 +373,12 @@ func (h Hosts) getIpPosition(ip string) int {
 
 	return -1
 }
+
+func buildRawLine(ip string, hosts []string) string {
+	output := ip
+	for _, host := range hosts {
+		output = fmt.Sprintf("%s %s", output, host)
+	}
+
+	return output
+}

hosts_test.go

@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"reflect"
 	"testing"
+
+	"github.com/stretchr/testify/assert"
 )
 
 func TestHostsLineIsComment(t *testing.T) {
@@ -255,3 +257,26 @@ func TestHostsClean(t *testing.T) {
 		t.Errorf("Clean did not update Raw properly: %s", hosts.Lines[0].ToRaw())
 	}
 }
+
+func TestHosts_Add(t *testing.T) {
+	hosts := new(Hosts)
+	assert.Nil(t, hosts.Add("127.0.0.2", "host1", "host2", "host3", "host4", "host5", "host6", "host7", "host8", "host9", "hosts10"))  // valid use with variatic args
+	assert.Error(t, assert.AnError, hosts.Add("127.0.0.2", "host11 host12 host13 host14 host15 host16 host17 host18 hosts19 hosts20")) // invalid use
+	assert.Len(t, hosts.Lines, 1)
+	assert.Nil(t, hosts.Add("127.0.0.3", "host1", "host2", "host3", "host4", "host5", "host6", "host7", "host8", "host9", "hosts10"))
+	assert.Len(t, hosts.Lines, 2)
+	assert.Error(t, assert.AnError, hosts.Add("127.0.0.3", "invalid hostname"))
+	assert.Error(t, assert.AnError, hosts.Add("127.0.0.3", ".invalid*hostname"))
+}
+
+func TestHosts_HostsPerLine(t *testing.T) {
+	hosts := new(Hosts)
+	assert.Nil(t, hosts.Add("127.0.0.2", "host1", "host2", "host3", "host4", "host5", "host6", "host7", "host8", "host9", "hosts10"))
+	assert.Nil(t, hosts.Add("127.0.0.2", "host11", "host12", "host13", "host14", "host15", "host16", "host17", "host18", "host19", "hosts20"))
+	hosts.HostsPerLine(1)
+	assert.Len(t, hosts.Lines, 20)
+	hosts.HostsPerLine(2)
+	assert.Len(t, hosts.Lines, 10)
+	hosts.HostsPerLine(9) // windows
+	assert.Len(t, hosts.Lines, 3)
+}

hostsline.go

@@ -17,7 +17,7 @@ type HostsLine struct {
 
 const commentChar string = "#"
 
-// Return a new instance of ```HostsLine```.
+// NewHostsLine return a new instance of ```HostsLine```.
 func NewHostsLine(raw string) HostsLine {
 	output := HostsLine{Raw: raw}
 	if output.IsComment() { //whole line is comment

slice.go

@@ -0,0 +1,29 @@
+package hostsfile
+
+func itemInSlice(item string, list []string) bool {
+	for _, i := range list {
+		if i == item {
+			return true
+		}
+	}
+
+	return false
+}
+
+func removeFromSlice(s string, slice []string) []string {
+	pos := findPositionInSlice(s, slice)
+	for pos > -1 {
+		slice = append(slice[:pos], slice[pos+1:]...)
+		pos = findPositionInSlice(s, slice)
+	}
+	return slice
+}
+
+func findPositionInSlice(s string, slice []string) int {
+	for index, v := range slice {
+		if v == s {
+			return index
+		}
+	}
+	return -1
+}

utils.go

@@ -1,52 +1,11 @@
+//go:build !windows
+
 package hostsfile
 
-import (
-	"fmt"
+const (
+	HostsPerLine  = -1 // unlimited
+	HostsFilePath = "/etc/hosts"
+	eol           = "\n"
 )
 
-func itemInSlice(item string, list []string) bool {
-	for _, i := range list {
-		if i == item {
-			return true
-		}
-	}
-
-	return false
-}
-
-func removeFromSlice(s string, slice []string) []string {
-	pos := findPositionInSlice(s, slice)
-	for pos > -1 {
-		slice = append(slice[:pos], slice[pos+1:]...)
-		pos = findPositionInSlice(s, slice)
-	}
-	return slice
-}
-
-func findPositionInSlice(s string, slice []string) int {
-	for index, v := range slice {
-		if v == s {
-			return index
-		}
-	}
-	return -1
-}
-
-//func sliceContainsItem(item string, list []string) bool {
-//	for _, i := range list {
-//		if strings.Contains(i, item) {
-//			return true
-//		}
-//	}
-//
-//	return false
-//}
-
-func buildRawLine(ip string, hosts []string) string {
-	output := ip
-	for _, host := range hosts {
-		output = fmt.Sprintf("%s %s", output, host)
-	}
-
-	return output
-}
+func (h *Hosts) preFlushClean() {} // no op

utils_windows.go

@@ -0,0 +1,12 @@
+package hostsfile
+
+const (
+	HostsFilePath = "${SystemRoot}/System32/drivers/etc/hosts"
+	HostsPerLine  = 9
+	eol           = "\r\n"
+)
+
+func (h *Hosts) preFlushClean() {
+	// need to force hosts per line always on windows see https://github.com/goodhosts/hostsfile/issues/18
+	h.HostsPerLine(HostsPerLine)
+}