source: irc_commands.c @ 00fd005

  /********************************************************************\
  * BitlBee -- An IRC to other IM-networks gateway                     *
  *                                                                    *
  * Copyright 2002-2010 Wilmer van der Gaast and others                *
  \********************************************************************/

/* IRC commands                                                         */

/*
  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License with
  the Debian GNU/Linux distribution in /usr/share/common-licenses/GPL;
  if not, write to the Free Software Foundation, Inc., 59 Temple Place,
  Suite 330, Boston, MA  02111-1307  USA
*/

#define BITLBEE_CORE
#include "bitlbee.h"
#include "help.h"
#include "ipc.h"

static void irc_cmd_pass( irc_t *irc, char **cmd )
{
        if( irc->status & USTATUS_LOGGED_IN )
        {
                char *send_cmd[] = { "identify", cmd[1], NULL };
                
                /* We're already logged in, this client seems to send the PASS
                   command last. (Possibly it won't send it at all if it turns
                   out we don't require it, which will break this feature.)
                   Try to identify using the given password. */
                root_command( irc, send_cmd );
                return;
        }
        /* Handling in pre-logged-in state, first see if this server is
           password-protected: */
        else if( global.conf->auth_pass &&
            ( strncmp( global.conf->auth_pass, "md5:", 4 ) == 0 ?
                md5_verify_password( cmd[1], global.conf->auth_pass + 4 ) == 0 :
                strcmp( cmd[1], global.conf->auth_pass ) == 0 ) )
        {
                irc->status |= USTATUS_AUTHORIZED;
                irc_check_login( irc );
        }
        else if( global.conf->auth_pass )
        {
                irc_send_num( irc, 464, ":Incorrect password" );
        }
        else
        {
                /* Remember the password and try to identify after USER/NICK. */
                irc_setpass( irc, cmd[1] );
                irc_check_login( irc );
        }
}

static void irc_cmd_user( irc_t *irc, char **cmd )
{
        irc->user->user = g_strdup( cmd[1] );
        irc->user->fullname = g_strdup( cmd[4] );
        
        irc_check_login( irc );
}

static void irc_cmd_nick( irc_t *irc, char **cmd )
{
        irc_user_t *iu;
        
        if( ( iu = irc_user_by_name( irc, cmd[1] ) ) && iu != irc->user )
        {
                irc_send_num( irc, 433, "%s :This nick is already in use", cmd[1] );
        }
        else if( !nick_ok( cmd[1] ) )
        {
                /* [SH] Invalid characters. */
                irc_send_num( irc, 432, "%s :This nick contains invalid characters", cmd[1] );
        }
        else if( irc->status & USTATUS_LOGGED_IN )
        {
                if( irc->status & USTATUS_IDENTIFIED )
                {
                        irc_setpass( irc, NULL );
                        irc->status &= ~USTATUS_IDENTIFIED;
                        irc_umode_set( irc, "-R", 1 );
                        irc_usermsg( irc, "Changing nicks resets your identify status. "
                                     "Re-identify or register a new account if you want "
                                     "your configuration to be saved. See \x02help "
                                     "nick_changes\x02." );
                }
                
                irc_user_set_nick( irc->user, cmd[1] );
        }
        else
        {
                g_free( irc->user->nick );
                irc->user->nick = g_strdup( cmd[1] );
                
                irc_check_login( irc );
        }
}

static void irc_cmd_quit( irc_t *irc, char **cmd )
{
        if( cmd[1] && *cmd[1] )
                irc_abort( irc, 0, "Quit: %s", cmd[1] );
        else
                irc_abort( irc, 0, "Leaving..." );
}

static void irc_cmd_ping( irc_t *irc, char **cmd )
{
        irc_write( irc, ":%s PONG %s :%s", irc->root->host,
                   irc->root->host, cmd[1]?cmd[1]:irc->root->host );
}

static void irc_cmd_pong( irc_t *irc, char **cmd )
{
        /* We could check the value we get back from the user, but in
           fact we don't care, we're just happy s/he's still alive. */
        irc->last_pong = gettime();
        irc->pinging = 0;
}

static void irc_cmd_join( irc_t *irc, char **cmd )
{
        char *comma, *s = cmd[1];
        
        while( s )
        {
                irc_channel_t *ic;
                
                if( ( comma = strchr( s, ',' ) ) )
                        *comma = '\0';
                
                if( ( ic = irc_channel_by_name( irc, s ) ) == NULL &&
                    ( ic = irc_channel_new( irc, s ) ) )
                {
                        if( strcmp( set_getstr( &ic->set, "type" ), "control" ) != 0 )
                        {
                                /* Autoconfiguration is for control channels only ATM. */
                        }
                        else if( bee_group_by_name( ic->irc->b, ic->name + 1, FALSE ) )
                        {
                                set_setstr( &ic->set, "group", ic->name + 1 );
                                set_setstr( &ic->set, "fill_by", "group" );
                        }
                        else if( set_setstr( &ic->set, "protocol", ic->name + 1 ) )
                        {
                                set_setstr( &ic->set, "fill_by", "protocol" );
                        }
                        else if( set_setstr( &ic->set, "account", ic->name + 1 ) )
                        {
                                set_setstr( &ic->set, "fill_by", "account" );
                        }
                        else
                        {
                                /* The set commands above will run this already,
                                   but if we didn't hit any, we have to fill the
                                   channel with the default population. */
                                bee_irc_channel_update( ic->irc, ic, NULL );
                        }
                }
                else if( ic == NULL )
                {
                        irc_send_num( irc, 479, "%s :Invalid channel name", s );
                        goto next;
                }
                
                if( ic->flags & IRC_CHANNEL_JOINED )
                        /* Dude, you're already there...
                           RFC doesn't have any reply for that though? */
                        goto next;
                
                if( ic->f->join && !ic->f->join( ic ) )
                        /* The story is: FALSE either means the handler
                           showed an error message, or is doing some work
                           before the join should be confirmed. (In the
                           latter case, the caller should take care of that
                           confirmation.) TRUE means all's good, let the
                           user join the channel right away. */
                        goto next;
                
                irc_channel_add_user( ic, irc->user );
                
next:
                if( comma )
                {
                        s = comma + 1;
                        *comma = ',';
                }
                else
                        break;
        }
}

static void irc_cmd_names( irc_t *irc, char **cmd )
{
        irc_channel_t *ic;
        
        if( cmd[1] && ( ic = irc_channel_by_name( irc, cmd[1] ) ) )
                irc_send_names( ic );
        /* With no args, we should show /names of all chans. Make the code
           below work well if necessary.
        else
        {
                GSList *l;
                
                for( l = irc->channels; l; l = l->next )
                        irc_send_names( l->data );
        }
        */
}

static void irc_cmd_part( irc_t *irc, char **cmd )
{
        irc_channel_t *ic;
        
        if( ( ic = irc_channel_by_name( irc, cmd[1] ) ) == NULL )
        {
                irc_send_num( irc, 403, "%s :No such channel", cmd[1] );
        }
        else if( irc_channel_del_user( ic, irc->user, IRC_CDU_PART, cmd[2] ) )
        {
                if( ic->f->part )
                        ic->f->part( ic, NULL );
        }
        else
        {
                irc_send_num( irc, 442, "%s :You're not on that channel", cmd[1] );
        }
}

static void irc_cmd_whois( irc_t *irc, char **cmd )
{
        char *nick = cmd[1];
        irc_user_t *iu = irc_user_by_name( irc, nick );
        
        if( iu )
                irc_send_whois( iu );
        else
                irc_send_num( irc, 401, "%s :Nick does not exist", nick );
}

static void irc_cmd_whowas( irc_t *irc, char **cmd )
{
        /* For some reason irssi tries a whowas when whois fails. We can
           ignore this, but then the user never gets a "user not found"
           message from irssi which is a bit annoying. So just respond
           with not-found and irssi users will get better error messages */
        
        irc_send_num( irc, 406, "%s :Nick does not exist", cmd[1] );
        irc_send_num( irc, 369, "%s :End of WHOWAS", cmd[1] );
}

static void irc_cmd_motd( irc_t *irc, char **cmd )
{
        irc_send_motd( irc );
}

static void irc_cmd_mode( irc_t *irc, char **cmd )
{
        if( irc_channel_name_ok( cmd[1] ) )
        {
                irc_channel_t *ic;
                
                if( ( ic = irc_channel_by_name( irc, cmd[1] ) ) == NULL )
                        irc_send_num( irc, 403, "%s :No such channel", cmd[1] );
                else if( cmd[2] )
                {
                        if( *cmd[2] == '+' || *cmd[2] == '-' )
                                irc_send_num( irc, 477, "%s :Can't change channel modes", cmd[1] );
                        else if( *cmd[2] == 'b' )
                                irc_send_num( irc, 368, "%s :No bans possible", cmd[1] );
                }
                else
                        irc_send_num( irc, 324, "%s +%s", cmd[1], ic->mode );
        }
        else
        {
                if( nick_cmp( cmd[1], irc->user->nick ) == 0 )
                {
                        if( cmd[2] )
                                irc_umode_set( irc, cmd[2], 0 );
                        else
                                irc_send_num( irc, 221, "+%s", irc->umode );
                }
                else
                        irc_send_num( irc, 502, ":Don't touch their modes" );
        }
}

static void irc_cmd_who( irc_t *irc, char **cmd )
{
        char *channel = cmd[1];
        irc_channel_t *ic;
        irc_user_t *iu;
        
        if( !channel || *channel == '0' || *channel == '*' || !*channel )
                irc_send_who( irc, irc->users, "**" );
        else if( ( ic = irc_channel_by_name( irc, channel ) ) )
                irc_send_who( irc, ic->users, channel );
        else if( ( iu = irc_user_by_name( irc, channel ) ) )
        {
                /* Tiny hack! */
                GSList *l = g_slist_append( NULL, iu );
                irc_send_who( irc, l, channel );
                g_slist_free( l );
        }
        else
                irc_send_num( irc, 403, "%s :No such channel", channel );
}

static void irc_cmd_privmsg( irc_t *irc, char **cmd )
{
        irc_channel_t *ic;
        irc_user_t *iu;
        
        if( !cmd[2] ) 
        {
                irc_send_num( irc, 412, ":No text to send" );
                return;
        }
        
        /* Don't treat CTCP actions as real CTCPs, just convert them right now. */
        if( g_strncasecmp( cmd[2], "\001ACTION", 7 ) == 0 )
        {
                cmd[2] += 4;
                memcpy( cmd[2], "/me", 3 );
                if( cmd[2][strlen(cmd[2])-1] == '\001' )
                        cmd[2][strlen(cmd[2])-1] = '\0';
        }
        
        if( irc_channel_name_ok( cmd[1] ) &&
            ( ic = irc_channel_by_name( irc, cmd[1] ) ) )
        {
                if( cmd[2][0] == '\001' )
                {
                        /* CTCPs to channels? Nah. Maybe later. */
                }
                else if( ic->f->privmsg )
                        ic->f->privmsg( ic, cmd[2] );
        }
        else if( ( iu = irc_user_by_name( irc, cmd[1] ) ) )
        {
                if( cmd[2][0] == '\001' )
                {
                        char **ctcp;
                        
                        if( iu->f->ctcp == NULL )
                                return;
                        if( cmd[2][strlen(cmd[2])-1] == '\001' )
                                cmd[2][strlen(cmd[2])-1] = '\0';
                        
                        ctcp = split_command_parts( cmd[2] + 1 );
                        iu->f->ctcp( iu, ctcp );
                }
                else if( iu->f->privmsg )
                {
                        iu->last_channel = NULL;
                        iu->f->privmsg( iu, cmd[2] );
                }
        }
        else
        {
                irc_send_num( irc, 401, "%s :No such nick/channel", cmd[1] );
        }
}

static void irc_cmd_notice( irc_t *irc, char **cmd )
{
        if( !cmd[2] ) 
        {
                irc_send_num( irc, 412, ":No text to send" );
                return;
        }
        
        /* At least for now just echo. IIRC some IRC clients use self-notices
           for lag checks, so try to support that. */
        if( nick_cmp( cmd[1], irc->user->nick ) == 0 )
                irc_send_msg( irc->user, "NOTICE", irc->user->nick, cmd[2], NULL );
}

static void irc_cmd_nickserv( irc_t *irc, char **cmd )
{
        /* [SH] This aliases the NickServ command to PRIVMSG root */
        /* [TV] This aliases the NS command to PRIVMSG root as well */
        root_command( irc, cmd + 1 );
}



static void irc_cmd_oper( irc_t *irc, char **cmd )
{
        account_t *a;
        
        /* /OPER can now also be used to enter IM passwords without echoing.
           It's a hack but the extra password security is worth it. */
        for( a = irc->b->accounts; a; a = a->next )
                if( strcmp( a->pass, PASSWORD_PENDING ) == 0 )
                {
                        set_setstr( &a->set, "password", cmd[2] );
                        irc_usermsg( irc, "Password added to IM account "
                                     "%s(%s)", a->prpl->name, a->user );
                        /* The IRC client may expect this. Report failure since
                           we didn't hand out a +o. */
                        irc_send_num( irc, 491, ":Password added to IM account "
                                      "%s(%s)", a->prpl->name, a->user );
                        return;
                }
        
        if( global.conf->oper_pass &&
            ( strncmp( global.conf->oper_pass, "md5:", 4 ) == 0 ?
                md5_verify_password( cmd[2], global.conf->oper_pass + 4 ) == 0 :
                strcmp( cmd[2], global.conf->oper_pass ) == 0 ) )
        {
                irc_umode_set( irc, "+o", 1 );
                irc_send_num( irc, 381, ":Password accepted" );
        }
        else
        {
                irc_send_num( irc, 491, ":Incorrect password" );
        }
}

static void irc_cmd_invite( irc_t *irc, char **cmd )
{
        irc_channel_t *ic;
        irc_user_t *iu;
        
        if( ( iu = irc_user_by_name( irc, cmd[1] ) ) == NULL )
        {
                irc_send_num( irc, 401, "%s :No such nick", cmd[1] );
                return;
        }
        else if( ( ic = irc_channel_by_name( irc, cmd[2] ) ) == NULL )
        {
                irc_send_num( irc, 403, "%s :No such channel", cmd[2] );
                return;
        }
        
        if( !ic->f->invite )
                irc_send_num( irc, 482, "%s :Can't invite people here", cmd[2] );
        else if( ic->f->invite( ic, iu ) )
                irc_send_num( irc, 341, "%s %s", iu->nick, ic->name );
}

static void irc_cmd_userhost( irc_t *irc, char **cmd )
{
        int i;
        
        /* [TV] Usable USERHOST-implementation according to
                RFC1459. Without this, mIRC shows an error
                while connecting, and the used way of rejecting
                breaks standards.
        */
        
        for( i = 1; cmd[i]; i ++ )
        {
                irc_user_t *iu = irc_user_by_name( irc, cmd[i] );
                
                if( iu )
                        irc_send_num( irc, 302, ":%s=%c%s@%s", iu->nick,
                                      irc_user_get_away( iu ) ? '-' : '+',
                                      iu->user, iu->host );
        }
}

static void irc_cmd_ison( irc_t *irc, char **cmd )
{
        char buff[IRC_MAX_LINE];
        int lenleft, i;
        
        buff[0] = '\0';
        
        /* [SH] Leave room for : and \0 */
        lenleft = IRC_MAX_LINE - 2;
        
        for( i = 1; cmd[i]; i ++ )
        {
                char *this, *next;
                
                this = cmd[i];
                while( *this )
                {
                        irc_user_t *iu;
                        
                        if( ( next = strchr( this, ' ' ) ) )
                                *next = 0;
                        
                        if( ( iu = irc_user_by_name( irc, this ) ) &&
                            iu->bu && iu->bu->flags & BEE_USER_ONLINE )
                        {
                                lenleft -= strlen( iu->nick ) + 1;
                                
                                if( lenleft < 0 )
                                        break;
                                
                                strcat( buff, iu->nick );
                                strcat( buff, " " );
                        }
                        
                        if( next )
                        {
                                *next = ' ';
                                this = next + 1;
                        }
                        else
                        {
                                break;
                        }    
                }
                
                /* *sigh* */
                if( lenleft < 0 )
                        break;
        }
        
        if( strlen( buff ) > 0 )
                buff[strlen(buff)-1] = '\0';
        
        irc_send_num( irc, 303, ":%s", buff );
}

static void irc_cmd_watch( irc_t *irc, char **cmd )
{
        int i;
        
        /* Obviously we could also mark a user structure as being
           watched, but what if the WATCH command is sent right
           after connecting? The user won't exist yet then... */
        for( i = 1; cmd[i]; i ++ )
        {
                char *nick;
                irc_user_t *iu;
                
                if( !cmd[i][0] || !cmd[i][1] )
                        break;
                
                nick = g_strdup( cmd[i] + 1 );
                nick_lc( nick );
                
                iu = irc_user_by_name( irc, nick );
                
                if( cmd[i][0] == '+' )
                {
                        if( !g_hash_table_lookup( irc->watches, nick ) )
                                g_hash_table_insert( irc->watches, nick, nick );
                        
                        if( iu && iu->bu && iu->bu->flags & BEE_USER_ONLINE )
                                irc_send_num( irc, 604, "%s %s %s %d :%s", iu->nick, iu->user,
                                              iu->host, (int) time( NULL ), "is online" );
                        else
                                irc_send_num( irc, 605, "%s %s %s %d :%s", nick, "*", "*",
                                              (int) time( NULL ), "is offline" );
                }
                else if( cmd[i][0] == '-' )
                {
                        gpointer okey, ovalue;
                        
                        if( g_hash_table_lookup_extended( irc->watches, nick, &okey, &ovalue ) )
                        {
                                g_hash_table_remove( irc->watches, okey );
                                g_free( okey );
                                
                                irc_send_num( irc, 602, "%s %s %s %d :%s", nick, "*", "*", 0, "Stopped watching" );
                        }
                }
        }
}

static void irc_cmd_topic( irc_t *irc, char **cmd )
{
        irc_channel_t *ic = irc_channel_by_name( irc, cmd[1] );
        const char *new = cmd[2];
        
        if( ic == NULL )
        {
                irc_send_num( irc, 403, "%s :No such channel", cmd[1] );
        }
        else if( new )
        {
                if( ic->f->topic == NULL )
                        irc_send_num( irc, 482, "%s :Can't change this channel's topic", ic->name );
                else if( ic->f->topic( ic, new ) )
                        irc_send_topic( ic, TRUE );
        }
        else
        {
                irc_send_topic( ic, FALSE );
        }
}

static void irc_cmd_away( irc_t *irc, char **cmd )
{
        if( cmd[1] && *cmd[1] )
        {
                char away[strlen(cmd[1])+1];
                int i, j;
                
                /* Copy away string, but skip control chars. Mainly because
                   Jabber really doesn't like them. */
                for( i = j = 0; cmd[1][i]; i ++ )
                        if( ( away[j] = cmd[1][i] ) >= ' ' )
                                j ++;
                away[j] = '\0';
                
                irc_send_num( irc, 306, ":You're now away: %s", away );
                set_setstr( &irc->b->set, "away", away );
        }
        else
        {
                irc_send_num( irc, 305, ":Welcome back" );
                set_setstr( &irc->b->set, "away", NULL );
        }
}

static void irc_cmd_list( irc_t *irc, char **cmd )
{
        GSList *l;
        
        for( l = irc->channels; l; l = l->next )
        {
                irc_channel_t *ic = l->data;
                
                irc_send_num( irc, 322, "%s %d :%s",
                              ic->name, g_slist_length( ic->users ), ic->topic ? : "" );
        }
        irc_send_num( irc, 323, ":%s", "End of /LIST" );
}

static void irc_cmd_version( irc_t *irc, char **cmd )
{
        irc_send_num( irc, 351, "bitlbee-%s. %s :%s/%s ",
                      BITLBEE_VERSION, irc->root->host, ARCH, CPU );
}

static void irc_cmd_completions( irc_t *irc, char **cmd )
{
        help_t *h;
        set_t *s;
        int i;
        
        irc_send_msg_raw( irc->root, "NOTICE", irc->user->nick, "COMPLETIONS OK" );
        
        for( i = 0; root_commands[i].command; i ++ )
                irc_send_msg_f( irc->root, "NOTICE", irc->user->nick, "COMPLETIONS %s", root_commands[i].command );
        
        for( h = global.help; h; h = h->next )
                irc_send_msg_f( irc->root, "NOTICE", irc->user->nick, "COMPLETIONS help %s", h->title );
        
        for( s = irc->b->set; s; s = s->next )
                irc_send_msg_f( irc->root, "NOTICE", irc->user->nick, "COMPLETIONS set %s", s->key );
        
        irc_send_msg_raw( irc->root, "NOTICE", irc->user->nick, "COMPLETIONS END" );
}

static void irc_cmd_rehash( irc_t *irc, char **cmd )
{
        if( global.conf->runmode == RUNMODE_INETD )
                ipc_master_cmd_rehash( NULL, NULL );
        else
                ipc_to_master( cmd );
        
        irc_send_num( irc, 382, "%s :Rehashing", global.conf_file );
}

static const command_t irc_commands[] = {
        { "pass",        1, irc_cmd_pass,        0 },
        { "user",        4, irc_cmd_user,        IRC_CMD_PRE_LOGIN },
        { "nick",        1, irc_cmd_nick,        0 },
        { "quit",        0, irc_cmd_quit,        0 },
        { "ping",        0, irc_cmd_ping,        0 },
        { "pong",        0, irc_cmd_pong,        IRC_CMD_LOGGED_IN },
        { "join",        1, irc_cmd_join,        IRC_CMD_LOGGED_IN },
        { "names",       1, irc_cmd_names,       IRC_CMD_LOGGED_IN },
        { "part",        1, irc_cmd_part,        IRC_CMD_LOGGED_IN },
        { "whois",       1, irc_cmd_whois,       IRC_CMD_LOGGED_IN },
        { "whowas",      1, irc_cmd_whowas,      IRC_CMD_LOGGED_IN },
        { "motd",        0, irc_cmd_motd,        IRC_CMD_LOGGED_IN },
        { "mode",        1, irc_cmd_mode,        IRC_CMD_LOGGED_IN },
        { "who",         0, irc_cmd_who,         IRC_CMD_LOGGED_IN },
        { "privmsg",     1, irc_cmd_privmsg,     IRC_CMD_LOGGED_IN },
        { "notice",      1, irc_cmd_notice,      IRC_CMD_LOGGED_IN },
        { "nickserv",    1, irc_cmd_nickserv,    IRC_CMD_LOGGED_IN },
        { "ns",          1, irc_cmd_nickserv,    IRC_CMD_LOGGED_IN },
        { "away",        0, irc_cmd_away,        IRC_CMD_LOGGED_IN },
        { "version",     0, irc_cmd_version,     IRC_CMD_LOGGED_IN },
        { "completions", 0, irc_cmd_completions, IRC_CMD_LOGGED_IN },
        { "userhost",    1, irc_cmd_userhost,    IRC_CMD_LOGGED_IN },
        { "ison",        1, irc_cmd_ison,        IRC_CMD_LOGGED_IN },
        { "watch",       1, irc_cmd_watch,       IRC_CMD_LOGGED_IN },
        { "invite",      2, irc_cmd_invite,      IRC_CMD_LOGGED_IN },
        { "topic",       1, irc_cmd_topic,       IRC_CMD_LOGGED_IN },
        { "oper",        2, irc_cmd_oper,        IRC_CMD_LOGGED_IN },
        { "list",        0, irc_cmd_list,        IRC_CMD_LOGGED_IN },
        { "die",         0, NULL,                IRC_CMD_OPER_ONLY | IRC_CMD_TO_MASTER },
        { "deaf",        0, NULL,                IRC_CMD_OPER_ONLY | IRC_CMD_TO_MASTER },
        { "wallops",     1, NULL,                IRC_CMD_OPER_ONLY | IRC_CMD_TO_MASTER },
        { "wall",        1, NULL,                IRC_CMD_OPER_ONLY | IRC_CMD_TO_MASTER },
        { "rehash",      0, irc_cmd_rehash,      IRC_CMD_OPER_ONLY },
        { "restart",     0, NULL,                IRC_CMD_OPER_ONLY | IRC_CMD_TO_MASTER },
        { "kill",        2, NULL,                IRC_CMD_OPER_ONLY | IRC_CMD_TO_MASTER },
        { NULL }
};

void irc_exec( irc_t *irc, char *cmd[] )
{       
        int i, n_arg;
        
        if( !cmd[0] )
                return;
        
        for( i = 0; irc_commands[i].command; i++ )
                if( g_strcasecmp( irc_commands[i].command, cmd[0] ) == 0 )
                {
                        /* There should be no typo in the next line: */
                        for( n_arg = 0; cmd[n_arg]; n_arg ++ ); n_arg --;
                        
                        if( irc_commands[i].flags & IRC_CMD_PRE_LOGIN && irc->status & USTATUS_LOGGED_IN )
                        {
                                irc_send_num( irc, 462, ":Only allowed before logging in" );
                        }
                        else if( irc_commands[i].flags & IRC_CMD_LOGGED_IN && !( irc->status & USTATUS_LOGGED_IN ) )
                        {
                                irc_send_num( irc, 451, ":Register first" );
                        }
                        else if( irc_commands[i].flags & IRC_CMD_OPER_ONLY && !strchr( irc->umode, 'o' ) )
                        {
                                irc_send_num( irc, 481, ":Permission denied - You're not an IRC operator" );
                        }
                        else if( n_arg < irc_commands[i].required_parameters )
                        {
                                irc_send_num( irc, 461, "%s :Need more parameters", cmd[0] );
                        }
                        else if( irc_commands[i].flags & IRC_CMD_TO_MASTER )
                        {
                                /* IPC doesn't make sense in inetd mode,
                                    but the function will catch that. */
                                ipc_to_master( cmd );
                        }
                        else
                        {
                                irc_commands[i].execute( irc, cmd );
                        }
                        
                        return;
                }
        
        if( irc->status >= USTATUS_LOGGED_IN )
                irc_send_num( irc, 421, "%s :Unknown command", cmd[0] );
}