123 lines
2.6 KiB
Go
123 lines
2.6 KiB
Go
package hosts
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import (
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"io"
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"os"
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"strings"
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)
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const readBufferSize = 8192
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func NewHostsFile(filePath string) (*File, error) {
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theHostFile := &File{
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filePath: filePath,
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}
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err := theHostFile.ReadHostsFile()
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if err == nil {
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return theHostFile, nil
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}
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return nil, err
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}
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type File struct {
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filePath string
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Entries []Entry
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lineEnding string
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}
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func (f *File) ReadHostsFile() error {
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f.Entries = nil
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theFile, err := os.Open(f.filePath)
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if err != nil {
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return err
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}
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defer theFile.Close()
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var lenIn int
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f.lineEnding = ""
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theCBuffer := ""
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theBuffer := make([]byte, readBufferSize)
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for err == nil {
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lenIn, err = theFile.Read(theBuffer)
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if lenIn > 0 {
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theCBuffer += string(theBuffer[:lenIn])
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if f.lineEnding == "" {
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if strings.Contains(theCBuffer, "\r\n") {
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f.lineEnding = "\r\n"
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} else if strings.Contains(theCBuffer, "\r") {
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f.lineEnding = "\r"
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} else if strings.Contains(theCBuffer, "\n") {
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f.lineEnding = "\n"
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}
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}
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if f.lineEnding == "\r\n" {
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strings.ReplaceAll(theCBuffer, "\r\n", "\n")
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} else if f.lineEnding == "\r" {
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strings.ReplaceAll(theCBuffer, "\r", "\n")
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}
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splt := strings.Split(theCBuffer, "\n")
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for i := 0; i < len(splt)-1; i++ {
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f.Entries = append(f.Entries, NewHostsEntry(splt[i]))
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}
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theCBuffer = splt[len(splt)-1]
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}
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}
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if err != io.EOF {
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return err
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}
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if theCBuffer != "" {
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f.Entries = append(f.Entries, NewHostsEntry(theCBuffer))
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}
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return nil
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}
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func (f File) WriteHostsFile() error {
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theFile, err := os.OpenFile(f.filePath, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0644)
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if err != nil {
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return err
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}
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defer theFile.Close()
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for _, entry := range f.Entries {
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_, err = theFile.WriteString(entry.ToLine() + f.lineEnding)
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if err != nil {
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return err
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}
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}
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return nil
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}
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func (f File) HasDomain(domain string) bool {
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for _, entry := range f.Entries {
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if entry.HasDomain(domain) {
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return true
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}
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}
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return false
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}
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func (f File) indexDomainSingleton(domain string) int {
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for i, entry := range f.Entries {
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if len(entry.Domains) == 1 && entry.HasDomain(domain) {
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return i
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}
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}
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return -1
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}
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func (f File) HasDomainSingleton(domain string) bool {
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return f.indexDomainSingleton(domain) > -1
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}
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func (f *File) OverwriteDomainSingleton(domain string, ipAddress string) {
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idx := f.indexDomainSingleton(domain)
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if idx == -1 {
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f.Entries = append(f.Entries, Entry{
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IPAddress: ipAddress,
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Domains: []string{domain},
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})
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} else {
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theEntry := f.Entries[idx]
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theEntry.IPAddress = ipAddress
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f.Entries = append(append(f.Entries[:idx], theEntry), f.Entries[idx+1:]...)
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}
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}
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