added list command to cli, along with new hosts methods ListHostsByIP…

…, ListHostsByCIDR and ListAddressesByHost

txeh.go

@@ -267,7 +267,54 @@ func (h *Hosts) AddHost(addressRaw string, hostRaw string) {
 	h.Unlock()
 }
 
-// HostAddressLookup returns true is the host is found, a string
+// ListHostsByIP returns a list of hostnames associated with a given IP address
+func (h *Hosts) ListHostsByIP(address string) []string {
+	var hosts []string
+
+	for _, hsl := range h.hostFileLines {
+		if hsl.Address == address {
+			hosts = append(hosts, hsl.Hostnames...)
+		}
+	}
+
+	return hosts
+}
+
+// ListAddressesByHost returns a list of IPs associated with a given hostname
+func (h *Hosts) ListAddressesByHost(hostname string, exact bool) [][]string {
+	var addresses [][]string
+
+	for _, hsl := range h.hostFileLines {
+		for _, hst := range hsl.Hostnames {
+			if hst == hostname {
+				addresses = append(addresses, []string{hsl.Address, hst})
+			}
+			if exact == false && hst != hostname && strings.Contains(hst, hostname) {
+				addresses = append(addresses, []string{hsl.Address, hst})
+			}
+		}
+	}
+
+	return addresses
+}
+
+// ListHostsByCIDR returns a list of IPs and hostnames associated with a given CIDR
+func (h *Hosts) ListHostsByCIDR(cidr string) [][]string {
+	var ipHosts [][]string
+
+	_, subnet, _ := net.ParseCIDR(cidr)
+	for _, hsl := range h.hostFileLines {
+		if subnet.Contains(net.ParseIP(hsl.Address)) {
+			for _, hst := range hsl.Hostnames {
+				ipHosts = append(ipHosts, []string{hsl.Address, hst})
+			}
+		}
+	}
+
+	return ipHosts
+}
+
+// HostAddressLookup returns true if the host is found, a string
 // containing the address and the index of the hfl
 func (h *Hosts) HostAddressLookup(host string, ipFamily IPFamily) (bool, string, int) {
 	h.Lock()

util/cmd/list.go

@@ -0,0 +1,28 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+)
+
+func init() {
+	rootCmd.AddCommand(listCmd)
+}
+
+var listCmd = &cobra.Command{
+	Use:   "list [BY_TYPE] [IP|CIDR] [IP|CIDR] [IP|CIDR] ...",
+	Short: "List hostnames for a IP addresses or CIDRs",
+	Long:  `List hostnames for a IP addresses or CIDRs present in /etc/hosts`,
+	Run: func(cmd *cobra.Command, args []string) {
+		err := cmd.Help()
+		if err != nil {
+			fmt.Printf("Error: can not display help, reason: %s\n", err.Error())
+			os.Exit(1)
+		}
+
+		fmt.Println("Please specify a sub-command such as \"ip\" or \"cidr\"")
+		os.Exit(1)
+	},
+}

util/cmd/list_cidr.go

@@ -0,0 +1,40 @@
+package cmd
+
+import (
+	"errors"
+	"fmt"
+	"github.com/spf13/cobra"
+)
+
+func init() {
+	listCmd.AddCommand(listByCidrCmd)
+}
+
+var listByCidrCmd = &cobra.Command{
+	Use:   "cidr [CIDR] [CIDR] [CIDR]...",
+	Short: "List hosts for one or more CIDRs",
+	Long:  `List hosts for one or more CIDRs from /etc/hosts`,
+	Args: func(cmd *cobra.Command, args []string) error {
+		if len(args) < 1 {
+			return errors.New("the \"list cidr\" command requires at least one CIDR address")
+		}
+
+		if ok, cidr := validateCIDRs(args); !ok {
+			return errors.New(fmt.Sprintf("\"%s\" is not a valid CIDR", cidr))
+		}
+
+		return nil
+	},
+	Run: func(cmd *cobra.Command, args []string) {
+		ListByCIDRs(args)
+	},
+}
+
+func ListByCIDRs(cidrs []string) {
+	for _, cidr := range cidrs {
+		ipHosts := etcHosts.ListHostsByCIDR(cidr)
+		for _, ih := range ipHosts {
+			fmt.Printf("%s %s %s\n", cidr, ih[0], ih[1])
+		}
+	}
+}

util/cmd/list_hosts.go

@@ -0,0 +1,43 @@
+package cmd
+
+import (
+	"errors"
+	"fmt"
+	"github.com/spf13/cobra"
+)
+
+var exactHost bool
+
+func init() {
+	listCmd.AddCommand(listByHostsCmd)
+	listByHostsCmd.PersistentFlags().BoolVarP(&exactHost, "exact", "e", false, "use -e for exact match")
+}
+
+var listByHostsCmd = &cobra.Command{
+	Use:   "host [hostname] [hostname] [hostname]...",
+	Short: "List IP for one or more hostnames",
+	Long:  `List IP for one or more hostnames from /etc/hosts`,
+	Args: func(cmd *cobra.Command, args []string) error {
+		if len(args) < 1 {
+			return errors.New("the \"list host\" command requires at least one hostname")
+		}
+
+		if ok, cidr := validateHostnames(args); !ok {
+			return errors.New(fmt.Sprintf("\"%s\" is not a valid hostname", cidr))
+		}
+
+		return nil
+	},
+	Run: func(cmd *cobra.Command, args []string) {
+		ListByHostnames(args)
+	},
+}
+
+func ListByHostnames(hostnames []string) {
+	for _, hn := range hostnames {
+		addrHosts := etcHosts.ListAddressesByHost(hn, exactHost)
+		for _, addrHost := range addrHosts {
+			fmt.Printf("%s %s\n", addrHost[0], addrHost[1])
+		}
+	}
+}

util/cmd/list_ip.go

@@ -0,0 +1,40 @@
+package cmd
+
+import (
+	"errors"
+	"fmt"
+	"github.com/spf13/cobra"
+)
+
+func init() {
+	listCmd.AddCommand(listByIpCmd)
+}
+
+var listByIpCmd = &cobra.Command{
+	Use:   "ip [IP] [IP] [IP]...",
+	Short: "List hosts for one or more IP addresses",
+	Long:  `List hosts for one or more IP addresses from /etc/hosts`,
+	Args: func(cmd *cobra.Command, args []string) error {
+		if len(args) < 1 {
+			return errors.New("the \"list ip\" command requires at least one IP address")
+		}
+
+		if ok, ip := validateIPAddresses(args); !ok {
+			return errors.New(fmt.Sprintf("\"%s\" is not a valid ip address", ip))
+		}
+
+		return nil
+	},
+	Run: func(cmd *cobra.Command, args []string) {
+		ListByIPs(args)
+	},
+}
+
+func ListByIPs(ips []string) {
+	for _, ip := range ips {
+		hosts := etcHosts.ListHostsByIP(ip)
+		for _, h := range hosts {
+			fmt.Printf("%s %s\n", ip, h)
+		}
+	}
+}

util/cmd/remove_cidr.go

@@ -23,8 +23,8 @@ var removeCidrCmd = &cobra.Command{
 			return errors.New("the \"remove cidr\" command requires at least one CIDR range to remove")
 		}
 
-		if ok, ip := validateCIDRs(args); !ok {
-			return errors.New(fmt.Sprintf("\"%s\" is not a valid CIDR", ip))
+		if ok, cidr := validateCIDRs(args); !ok {
+			return errors.New(fmt.Sprintf("\"%s\" is not a valid CIDR", cidr))
 		}
 
 		return nil