Add ChanServ and NickServ LIST commands.

These commands search the registered nicknames/channels for ones
matching the provided regex, or return the entire list.

Only operators with chanreg (for ChanServ) or accreg (for NickServ)
capabilities can use LIST.

irc/accounts.go

@@ -1047,6 +1047,17 @@ func (am *AccountManager) AuthenticateByPassphrase(client *Client, accountName s
 	return err
 }
 
+func (am *AccountManager) AllNicks() []string {
+	am.RLock()
+	defer am.RUnlock()
+
+	nicks := make([]string, 0, len(am.nickToAccount))
+	for nick := range am.nickToAccount {
+		nicks = append(nicks, nick)
+	}
+	return nicks
+}
+
 func (am *AccountManager) LoadAccount(accountName string) (result ClientAccount, err error) {
 	casefoldedAccount, err := CasefoldName(accountName)
 	if err != nil {

irc/chanserv.go

@@ -5,6 +5,7 @@ package irc
 
 import (
 	"fmt"
+	"regexp"
 	"sort"
 	"strings"
 	"time"
@@ -126,6 +127,16 @@ set using PURGE.`,
 			capabs:    []string{"chanreg"},
 			minParams: 1,
 		},
+		"list": {
+			handler: csListHandler,
+			help: `Syntax: $bLIST [regex]$b
+
+LIST returns the list of registered channels, which match the given regex.
+If no regex is provided, all registered channels are returned.`,
+			helpShort: `$bLIST$b searches the list of registered channels.`,
+			capabs:    []string{"chanreg"},
+			minParams: 0,
+		},
 		"info": {
 			handler: csInfoHandler,
 			help: `Syntax: $INFO #channel$b
@@ -559,6 +570,34 @@ func csUnpurgeHandler(server *Server, client *Client, command string, params []s
 	}
 }
 
+func csListHandler(server *Server, client *Client, command string, params []string, rb *ResponseBuffer) {
+	if !client.HasRoleCapabs("chanreg") {
+		csNotice(rb, client.t("Insufficient privileges"))
+		return
+	}
+
+	var searchRegex *regexp.Regexp
+	if len(params) > 0 {
+		var err error
+		searchRegex, err = regexp.Compile(params[0])
+		if err != nil {
+			csNotice(rb, client.t("Invalid regex"))
+			return
+		}
+	}
+
+	csNotice(rb, ircfmt.Unescape(client.t("*** $bChanServ LIST$b ***")))
+
+	channels := server.channelRegistry.AllChannels()
+	for _, channel := range channels {
+		if searchRegex == nil || searchRegex.MatchString(channel) {
+			csNotice(rb, fmt.Sprintf("    %s", channel))
+		}
+	}
+
+	csNotice(rb, ircfmt.Unescape(client.t("*** $bEnd of ChanServ LIST$b ***")))
+}
+
 func csInfoHandler(server *Server, client *Client, command string, params []string, rb *ResponseBuffer) {
 	chname, err := CasefoldChannel(params[0])
 	if err != nil {

irc/nickserv.go

@@ -5,6 +5,7 @@ package irc
 
 import (
 	"fmt"
+	"regexp"
 	"strconv"
 	"strings"
 	"time"
@@ -97,6 +98,17 @@ certfp (your client certificate) if a password is not given.`,
 			enabled:   servCmdRequiresAuthEnabled,
 			minParams: 1,
 		},
+		"list": {
+			handler: nsListHandler,
+			help: `Syntax: $bLIST [regex]$b
+
+LIST returns the list of registered nicknames, which match the given regex.
+If no regex is provided, all registered nicknames are returned.`,
+			helpShort: `$bLIST$b searches the list of registered nicknames.`,
+			enabled:   servCmdRequiresAuthEnabled,
+			capabs:    []string{"accreg"},
+			minParams: 0,
+		},
 		"info": {
 			handler: nsInfoHandler,
 			help: `Syntax: $bINFO [username]$b
@@ -681,6 +693,34 @@ func nsIdentifyHandler(server *Server, client *Client, command string, params []
 	}
 }
 
+func nsListHandler(server *Server, client *Client, command string, params []string, rb *ResponseBuffer) {
+	if !client.HasRoleCapabs("accreg") {
+		nsNotice(rb, client.t("Insufficient privileges"))
+		return
+	}
+
+	var searchRegex *regexp.Regexp
+	if len(params) > 0 {
+		var err error
+		searchRegex, err = regexp.Compile(params[0])
+		if err != nil {
+			nsNotice(rb, client.t("Invalid regex"))
+			return
+		}
+	}
+
+	nsNotice(rb, ircfmt.Unescape(client.t("*** $bNickServ LIST$b ***")))
+
+	nicks := server.accounts.AllNicks()
+	for _, nick := range nicks {
+		if searchRegex == nil || searchRegex.MatchString(nick) {
+			nsNotice(rb, fmt.Sprintf("    %s", nick))
+		}
+	}
+
+	nsNotice(rb, ircfmt.Unescape(client.t("*** $bEnd of NickServ LIST$b ***")))
+}
+
 func nsInfoHandler(server *Server, client *Client, command string, params []string, rb *ResponseBuffer) {
 	if !server.Config().Accounts.AuthenticationEnabled && !client.HasRoleCapabs("accreg") {
 		nsNotice(rb, client.t("This command has been disabled by the server administrators"))