cli.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2006, Digium, Inc.
 *
 * Mark Spencer <markster@digium.com>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief Standard Command Line Interface
 *
 * \author Mark Spencer <markster@digium.com> 
 */

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision: 236899 $")

#include "asterisk/_private.h"
#include "asterisk/paths.h"   /* use ast_config_AST_MODULE_DIR */
#include <sys/signal.h>
#include <signal.h>
#include <ctype.h>
#include <regex.h>
#include <pwd.h>
#include <grp.h>

#include <readline.h>

#include "asterisk/cli.h"
#include "asterisk/linkedlists.h"
#include "asterisk/module.h"
#include "asterisk/pbx.h"
#include "asterisk/channel.h"
#include "asterisk/utils.h"
#include "asterisk/app.h"
#include "asterisk/lock.h"
#include "asterisk/threadstorage.h"

/*!
 * \brief List of restrictions per user.
 */
struct cli_perm {
   unsigned int permit:1;           /*!< 1=Permit 0=Deny */
   char *command;          /*!< Command name (to apply restrictions) */
   AST_LIST_ENTRY(cli_perm) list;
};

AST_LIST_HEAD_NOLOCK(cli_perm_head, cli_perm);

/*! \brief list of users to apply restrictions. */
struct usergroup_cli_perm {
   int uid;          /*!< User ID (-1 disabled) */
   int gid;          /*!< Group ID (-1 disabled) */
   struct cli_perm_head *perms;     /*!< List of permissions. */
   AST_LIST_ENTRY(usergroup_cli_perm) list;/*!< List mechanics */
};
/*! \brief CLI permissions config file. */
static const char perms_config[] = "cli_permissions.conf";
/*! \brief Default permissions value 1=Permit 0=Deny */
static int cli_default_perm = 1;

/*! \brief mutex used to prevent a user from running the 'cli reload permissions' command while
 * it is already running. */
AST_MUTEX_DEFINE_STATIC(permsconfiglock);
/*! \brief  List of users and permissions. */
AST_RWLIST_HEAD_STATIC(cli_perms, usergroup_cli_perm);

/*!
 * \brief map a debug or verbose value to a filename
 */
struct ast_debug_file {
   unsigned int level;
   AST_RWLIST_ENTRY(ast_debug_file) entry;
   char filename[0];
};

AST_RWLIST_HEAD(debug_file_list, ast_debug_file);

/*! list of filenames and their debug settings */
static struct debug_file_list debug_files;
/*! list of filenames and their verbose settings */
static struct debug_file_list verbose_files;

AST_THREADSTORAGE(ast_cli_buf);

/*! \brief Initial buffer size for resulting strings in ast_cli() */
#define AST_CLI_INITLEN   256

void ast_cli(int fd, const char *fmt, ...)
{
   int res;
   struct ast_str *buf;
   va_list ap;

   if (!(buf = ast_str_thread_get(&ast_cli_buf, AST_CLI_INITLEN)))
      return;

   va_start(ap, fmt);
   res = ast_str_set_va(&buf, 0, fmt, ap);
   va_end(ap);

   if (res != AST_DYNSTR_BUILD_FAILED) {
      ast_carefulwrite(fd, ast_str_buffer(buf), ast_str_strlen(buf), 100);
   }
}

unsigned int ast_debug_get_by_file(const char *file) 
{
   struct ast_debug_file *adf;
   unsigned int res = 0;

   AST_RWLIST_RDLOCK(&debug_files);
   AST_LIST_TRAVERSE(&debug_files, adf, entry) {
      if (!strncasecmp(adf->filename, file, strlen(adf->filename))) {
         res = adf->level;
         break;
      }
   }
   AST_RWLIST_UNLOCK(&debug_files);

   return res;
}

unsigned int ast_verbose_get_by_file(const char *file) 
{
   struct ast_debug_file *adf;
   unsigned int res = 0;

   AST_RWLIST_RDLOCK(&verbose_files);
   AST_LIST_TRAVERSE(&verbose_files, adf, entry) {
      if (!strncasecmp(adf->filename, file, strlen(file))) {
         res = adf->level;
         break;
      }
   }
   AST_RWLIST_UNLOCK(&verbose_files);

   return res;
}

/*! \internal
 *  \brief Check if the user with 'uid' and 'gid' is allow to execute 'command',
 *    if command starts with '_' then not check permissions, just permit
 *    to run the 'command'.
 *    if uid == -1 or gid == -1 do not check permissions.
 *    if uid == -2 and gid == -2 is because rasterisk client didn't send
 *    the credentials, so the cli_default_perm will be applied.
 *  \param uid User ID.
 *  \param gid Group ID.
 *  \param command Command name to check permissions.
 *  \retval 1 if has permission
 *  \retval 0 if it is not allowed.
 */
static int cli_has_permissions(int uid, int gid, const char *command)
{
   struct usergroup_cli_perm *user_perm;
   struct cli_perm *perm;
   /* set to the default permissions general option. */
   int isallowg = cli_default_perm, isallowu = -1, ispattern;
   regex_t regexbuf;

   /* if uid == -1 or gid == -1 do not check permissions.
      if uid == -2 and gid == -2 is because rasterisk client didn't send
      the credentials, so the cli_default_perm will be applied. */
   if ((uid == CLI_NO_PERMS && gid == CLI_NO_PERMS) || command[0] == '_') {
      return 1;
   }

   if (gid < 0 && uid < 0) {
      return cli_default_perm;
   }

   AST_RWLIST_RDLOCK(&cli_perms);
   AST_LIST_TRAVERSE(&cli_perms, user_perm, list) {
      if (user_perm->gid != gid && user_perm->uid != uid) {
         continue;
      }
      AST_LIST_TRAVERSE(user_perm->perms, perm, list) {
         if (strcasecmp(perm->command, "all") && strncasecmp(perm->command, command, strlen(perm->command))) {
            /* if the perm->command is a pattern, check it against command. */
            ispattern = !regcomp(&regexbuf, perm->command, REG_EXTENDED | REG_NOSUB | REG_ICASE);
            if (ispattern && regexec(&regexbuf, command, 0, NULL, 0)) {
               regfree(&regexbuf);
               continue;
            }
            if (!ispattern) {
               continue;
            }
            regfree(&regexbuf);
         }
         if (user_perm->uid == uid) {
            /* this is a user definition. */
            isallowu = perm->permit;
         } else {
            /* otherwise is a group definition. */
            isallowg = perm->permit;
         }
      }
   }
   AST_RWLIST_UNLOCK(&cli_perms);
   if (isallowu > -1) {
      /* user definition override group definition. */
      isallowg = isallowu;
   }

   return isallowg;
}

static AST_RWLIST_HEAD_STATIC(helpers, ast_cli_entry);

static char *complete_fn(const char *word, int state)
{
   char *c, *d;
   char filename[PATH_MAX];

   if (word[0] == '/')
      ast_copy_string(filename, word, sizeof(filename));
   else
      snprintf(filename, sizeof(filename), "%s/%s", ast_config_AST_MODULE_DIR, word);

   c = d = filename_completion_function(filename, state);
   
   if (c && word[0] != '/')
      c += (strlen(ast_config_AST_MODULE_DIR) + 1);
   if (c)
      c = ast_strdup(c);

   free(d);
   
   return c;
}

static char *handle_load(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   /* "module load <mod>" */
   switch (cmd) {
   case CLI_INIT:
      e->command = "module load";
      e->usage =
         "Usage: module load <module name>\n"
         "       Loads the specified module into Asterisk.\n";
      return NULL;

   case CLI_GENERATE:
      if (a->pos != e->args)
         return NULL;
      return complete_fn(a->word, a->n);
   }
   if (a->argc != e->args + 1)
      return CLI_SHOWUSAGE;
   if (ast_load_resource(a->argv[e->args])) {
      ast_cli(a->fd, "Unable to load module %s\n", a->argv[e->args]);
      return CLI_FAILURE;
   }
   return CLI_SUCCESS;
}

static char *handle_reload(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   int x;

   switch (cmd) {
   case CLI_INIT:
      e->command = "module reload";
      e->usage =
         "Usage: module reload [module ...]\n"
         "       Reloads configuration files for all listed modules which support\n"
         "       reloading, or for all supported modules if none are listed.\n";
      return NULL;

   case CLI_GENERATE:
      return ast_module_helper(a->line, a->word, a->pos, a->n, a->pos, 1);
   }
   if (a->argc == e->args) {
      ast_module_reload(NULL);
      return CLI_SUCCESS;
   }
   for (x = e->args; x < a->argc; x++) {
      int res = ast_module_reload(a->argv[x]);
      /* XXX reload has multiple error returns, including -1 on error and 2 on success */
      switch (res) {
      case 0:
         ast_cli(a->fd, "No such module '%s'\n", a->argv[x]);
         break;
      case 1:
         ast_cli(a->fd, "Module '%s' does not support reload\n", a->argv[x]);
         break;
      }
   }
   return CLI_SUCCESS;
}

/*! 
 * \brief Find the debug or verbose file setting 
 * \arg debug 1 for debug, 0 for verbose
 */
static struct ast_debug_file *find_debug_file(const char *fn, unsigned int debug)
{
   struct ast_debug_file *df = NULL;
   struct debug_file_list *dfl = debug ? &debug_files : &verbose_files;

   AST_LIST_TRAVERSE(dfl, df, entry) {
      if (!strcasecmp(df->filename, fn))
         break;
   }

   return df;
}

static char *complete_number(const char *partial, unsigned int min, unsigned int max, int n)
{
   int i, count = 0;
   unsigned int prospective[2];
   unsigned int part = strtoul(partial, NULL, 10);
   char next[12];

   if (part < min || part > max) {
      return NULL;
   }

   for (i = 0; i < 21; i++) {
      if (i == 0) {
         prospective[0] = prospective[1] = part;
      } else if (part == 0 && !ast_strlen_zero(partial)) {
         break;
      } else if (i < 11) {
         prospective[0] = prospective[1] = part * 10 + (i - 1);
      } else {
         prospective[0] = (part * 10 + (i - 11)) * 10;
         prospective[1] = prospective[0] + 9;
      }
      if (i < 11 && (prospective[0] < min || prospective[0] > max)) {
         continue;
      } else if (prospective[1] < min || prospective[0] > max) {
         continue;
      }

      if (++count > n) {
         if (i < 11) {
            snprintf(next, sizeof(next), "%u", prospective[0]);
         } else {
            snprintf(next, sizeof(next), "%u...", prospective[0] / 10);
         }
         return ast_strdup(next);
      }
   }
   return NULL;
}

static char *handle_verbose(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   int oldval;
   int newlevel;
   int atleast = 0;
   int fd = a->fd;
   int argc = a->argc;
   char **argv = a->argv;
   char *argv3 = a->argv ? S_OR(a->argv[3], "") : "";
   int *dst;
   char *what;
   struct debug_file_list *dfl;
   struct ast_debug_file *adf;
   char *fn;

   switch (cmd) {
   case CLI_INIT:
      e->command = "core set {debug|verbose}";
      e->usage =
#if !defined(LOW_MEMORY)
         "Usage: core set {debug|verbose} [atleast] <level> [filename]\n"
#else
         "Usage: core set {debug|verbose} [atleast] <level>\n"
#endif
         "       core set {debug|verbose} off\n"
#if !defined(LOW_MEMORY)
         "       Sets level of debug or verbose messages to be displayed or \n"
         "       sets a filename to display debug messages from.\n"
#else
         "       Sets level of debug or verbose messages to be displayed.\n"
#endif
         "  0 or off means no messages should be displayed.\n"
         "  Equivalent to -d[d[...]] or -v[v[v...]] on startup\n";
      return NULL;

   case CLI_GENERATE:
      if (a->pos == 3 || (a->pos == 4 && !strcasecmp(a->argv[3], "atleast"))) {
         char *pos = a->pos == 3 ? argv3 : S_OR(a->argv[4], "");
         int numbermatch = (ast_strlen_zero(pos) || strchr("123456789", pos[0])) ? 0 : 21;
         if (a->n < 21 && numbermatch == 0) {
            return complete_number(pos, 0, 0x7fffffff, a->n);
         } else if (pos[0] == '0') {
            if (a->n == 0) {
               return ast_strdup("0");
            } else {
               return NULL;
            }
         } else if (a->n == (21 - numbermatch)) {
            if (a->pos == 3 && !strncasecmp(argv3, "off", strlen(argv3))) {
               return ast_strdup("off");
            } else if (a->pos == 3 && !strncasecmp(argv3, "atleast", strlen(argv3))) {
               return ast_strdup("atleast");
            }
         } else if (a->n == (22 - numbermatch) && a->pos == 3 && ast_strlen_zero(argv3)) {
            return ast_strdup("atleast");
         }
#if !defined(LOW_MEMORY)
      } else if (a->pos == 4 || (a->pos == 5 && !strcasecmp(argv3, "atleast"))) {
         return ast_complete_source_filename(a->pos == 4 ? S_OR(a->argv[4], "") : S_OR(a->argv[5], ""), a->n);
#endif
      }
      return NULL;
   }
   /* all the above return, so we proceed with the handler.
    * we are guaranteed to be called with argc >= e->args;
    */

   if (argc <= e->args)
      return CLI_SHOWUSAGE;
   if (!strcasecmp(argv[e->args - 1], "debug")) {
      dst = &option_debug;
      oldval = option_debug;
      what = "Core debug";
   } else {
      dst = &option_verbose;
      oldval = option_verbose;
      what = "Verbosity";
   }
   if (argc == e->args + 1 && !strcasecmp(argv[e->args], "off")) {
      unsigned int debug = (*what == 'C');
      newlevel = 0;

      dfl = debug ? &debug_files : &verbose_files;

      AST_RWLIST_WRLOCK(dfl);
      while ((adf = AST_RWLIST_REMOVE_HEAD(dfl, entry)))
         ast_free(adf);
      ast_clear_flag(&ast_options, debug ? AST_OPT_FLAG_DEBUG_FILE : AST_OPT_FLAG_VERBOSE_FILE);
      AST_RWLIST_UNLOCK(dfl);

      goto done;
   }
   if (!strcasecmp(argv[e->args], "atleast"))
      atleast = 1;
   if (argc != e->args + atleast + 1 && argc != e->args + atleast + 2)
      return CLI_SHOWUSAGE;
   if (sscanf(argv[e->args + atleast], "%30d", &newlevel) != 1)
      return CLI_SHOWUSAGE;
   if (argc == e->args + atleast + 2) {
      unsigned int debug = (*what == 'C');
      dfl = debug ? &debug_files : &verbose_files;

      fn = argv[e->args + atleast + 1];

      AST_RWLIST_WRLOCK(dfl);

      if ((adf = find_debug_file(fn, debug)) && !newlevel) {
         AST_RWLIST_REMOVE(dfl, adf, entry);
         if (AST_RWLIST_EMPTY(dfl))
            ast_clear_flag(&ast_options, debug ? AST_OPT_FLAG_DEBUG_FILE : AST_OPT_FLAG_VERBOSE_FILE);
         AST_RWLIST_UNLOCK(dfl);
         ast_cli(fd, "%s was %d and has been set to 0 for '%s'\n", what, adf->level, fn);
         ast_free(adf);
         return CLI_SUCCESS;
      }

      if (adf) {
         if ((atleast && newlevel < adf->level) || adf->level == newlevel) {
            ast_cli(fd, "%s is %d for '%s'\n", what, adf->level, fn);
            AST_RWLIST_UNLOCK(dfl);
            return CLI_SUCCESS;
         }
      } else if (!(adf = ast_calloc(1, sizeof(*adf) + strlen(fn) + 1))) {
         AST_RWLIST_UNLOCK(dfl);
         return CLI_FAILURE;
      }

      oldval = adf->level;
      adf->level = newlevel;
      strcpy(adf->filename, fn);

      ast_set_flag(&ast_options, debug ? AST_OPT_FLAG_DEBUG_FILE : AST_OPT_FLAG_VERBOSE_FILE);

      AST_RWLIST_INSERT_TAIL(dfl, adf, entry);
      AST_RWLIST_UNLOCK(dfl);

      ast_cli(fd, "%s was %d and has been set to %d for '%s'\n", what, oldval, adf->level, adf->filename);

      return CLI_SUCCESS;
   }

done:
   if (!atleast || newlevel > *dst)
      *dst = newlevel;
   if (oldval > 0 && *dst == 0)
      ast_cli(fd, "%s is now OFF\n", what);
   else if (*dst > 0) {
      if (oldval == *dst)
         ast_cli(fd, "%s is at least %d\n", what, *dst);
      else
         ast_cli(fd, "%s was %d and is now %d\n", what, oldval, *dst);
   }

   return CLI_SUCCESS;
}

static char *handle_logger_mute(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   switch (cmd) {
   case CLI_INIT:
      e->command = "logger mute";
      e->usage = 
         "Usage: logger mute\n"
         "       Disables logging output to the current console, making it possible to\n"
         "       gather information without being disturbed by scrolling lines.\n";
      return NULL;
   case CLI_GENERATE:
      return NULL;
   }

   if (a->argc < 2 || a->argc > 3)
      return CLI_SHOWUSAGE;

   if (a->argc == 3 && !strcasecmp(a->argv[2], "silent"))
      ast_console_toggle_mute(a->fd, 1);
   else
      ast_console_toggle_mute(a->fd, 0);

   return CLI_SUCCESS;
}

static char *handle_unload(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   /* "module unload mod_1 [mod_2 .. mod_N]" */
   int x;
   int force = AST_FORCE_SOFT;
   char *s;

   switch (cmd) {
   case CLI_INIT:
      e->command = "module unload";
      e->usage =
         "Usage: module unload [-f|-h] <module_1> [<module_2> ... ]\n"
         "       Unloads the specified module from Asterisk. The -f\n"
         "       option causes the module to be unloaded even if it is\n"
         "       in use (may cause a crash) and the -h module causes the\n"
         "       module to be unloaded even if the module says it cannot, \n"
         "       which almost always will cause a crash.\n";
      return NULL;

   case CLI_GENERATE:
      return ast_module_helper(a->line, a->word, a->pos, a->n, a->pos, 0);
   }
   if (a->argc < e->args + 1)
      return CLI_SHOWUSAGE;
   x = e->args;   /* first argument */
   s = a->argv[x];
   if (s[0] == '-') {
      if (s[1] == 'f')
         force = AST_FORCE_FIRM;
      else if (s[1] == 'h')
         force = AST_FORCE_HARD;
      else
         return CLI_SHOWUSAGE;
      if (a->argc < e->args + 2) /* need at least one module name */
         return CLI_SHOWUSAGE;
      x++;  /* skip this argument */
   }

   for (; x < a->argc; x++) {
      if (ast_unload_resource(a->argv[x], force)) {
         ast_cli(a->fd, "Unable to unload resource %s\n", a->argv[x]);
         return CLI_FAILURE;
      }
   }
   return CLI_SUCCESS;
}

#define MODLIST_FORMAT  "%-30s %-40.40s %-10d\n"
#define MODLIST_FORMAT2 "%-30s %-40.40s %-10s\n"

AST_MUTEX_DEFINE_STATIC(climodentrylock);
static int climodentryfd = -1;

static int modlist_modentry(const char *module, const char *description, int usecnt, const char *like)
{
   /* Comparing the like with the module */
   if (strcasestr(module, like) ) {
      ast_cli(climodentryfd, MODLIST_FORMAT, module, description, usecnt);
      return 1;
   } 
   return 0;
}

static void print_uptimestr(int fd, struct timeval timeval, const char *prefix, int printsec)
{
   int x; /* the main part - years, weeks, etc. */
   struct ast_str *out;

#define SECOND (1)
#define MINUTE (SECOND*60)
#define HOUR (MINUTE*60)
#define DAY (HOUR*24)
#define WEEK (DAY*7)
#define YEAR (DAY*365)
#define NEEDCOMMA(x) ((x)? ",": "") /* define if we need a comma */
   if (timeval.tv_sec < 0) /* invalid, nothing to show */
      return;

   if (printsec)  {  /* plain seconds output */
      ast_cli(fd, "%s: %lu\n", prefix, (u_long)timeval.tv_sec);
      return;
   }
   out = ast_str_alloca(256);
   if (timeval.tv_sec > YEAR) {
      x = (timeval.tv_sec / YEAR);
      timeval.tv_sec -= (x * YEAR);
      ast_str_append(&out, 0, "%d year%s%s ", x, ESS(x),NEEDCOMMA(timeval.tv_sec));
   }
   if (timeval.tv_sec > WEEK) {
      x = (timeval.tv_sec / WEEK);
      timeval.tv_sec -= (x * WEEK);
      ast_str_append(&out, 0, "%d week%s%s ", x, ESS(x),NEEDCOMMA(timeval.tv_sec));
   }
   if (timeval.tv_sec > DAY) {
      x = (timeval.tv_sec / DAY);
      timeval.tv_sec -= (x * DAY);
      ast_str_append(&out, 0, "%d day%s%s ", x, ESS(x),NEEDCOMMA(timeval.tv_sec));
   }
   if (timeval.tv_sec > HOUR) {
      x = (timeval.tv_sec / HOUR);
      timeval.tv_sec -= (x * HOUR);
      ast_str_append(&out, 0, "%d hour%s%s ", x, ESS(x),NEEDCOMMA(timeval.tv_sec));
   }
   if (timeval.tv_sec > MINUTE) {
      x = (timeval.tv_sec / MINUTE);
      timeval.tv_sec -= (x * MINUTE);
      ast_str_append(&out, 0, "%d minute%s%s ", x, ESS(x),NEEDCOMMA(timeval.tv_sec));
   }
   x = timeval.tv_sec;
   if (x > 0 || ast_str_strlen(out) == 0) /* if there is nothing, print 0 seconds */
      ast_str_append(&out, 0, "%d second%s ", x, ESS(x));
   ast_cli(fd, "%s: %s\n", prefix, ast_str_buffer(out));
}

static struct ast_cli_entry *cli_next(struct ast_cli_entry *e)
{
   if (e) {
      return AST_LIST_NEXT(e, list);
   } else {
      return AST_LIST_FIRST(&helpers);
   }
}

static char * handle_showuptime(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   struct timeval curtime = ast_tvnow();
   int printsec;

   switch (cmd) {
   case CLI_INIT:
      e->command = "core show uptime [seconds]";
      e->usage =
         "Usage: core show uptime [seconds]\n"
         "       Shows Asterisk uptime information.\n"
         "       The seconds word returns the uptime in seconds only.\n";
      return NULL;

   case CLI_GENERATE:
      return NULL;
   }
   /* regular handler */
   if (a->argc == e->args && !strcasecmp(a->argv[e->args-1],"seconds"))
      printsec = 1;
   else if (a->argc == e->args-1)
      printsec = 0;
   else
      return CLI_SHOWUSAGE;
   if (ast_startuptime.tv_sec)
      print_uptimestr(a->fd, ast_tvsub(curtime, ast_startuptime), "System uptime", printsec);
   if (ast_lastreloadtime.tv_sec)
      print_uptimestr(a->fd, ast_tvsub(curtime, ast_lastreloadtime), "Last reload", printsec);
   return CLI_SUCCESS;
}

static char *handle_modlist(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   char *like;

   switch (cmd) {
   case CLI_INIT:
      e->command = "module show [like]";
      e->usage =
         "Usage: module show [like keyword]\n"
         "       Shows Asterisk modules currently in use, and usage statistics.\n";
      return NULL;

   case CLI_GENERATE:
      if (a->pos == e->args)
         return ast_module_helper(a->line, a->word, a->pos, a->n, a->pos, 0);
      else
         return NULL;
   }
   /* all the above return, so we proceed with the handler.
    * we are guaranteed to have argc >= e->args
    */
   if (a->argc == e->args - 1)
      like = "";
   else if (a->argc == e->args + 1 && !strcasecmp(a->argv[e->args-1], "like") )
      like = a->argv[e->args];
   else
      return CLI_SHOWUSAGE;
      
   ast_mutex_lock(&climodentrylock);
   climodentryfd = a->fd; /* global, protected by climodentrylock */
   ast_cli(a->fd, MODLIST_FORMAT2, "Module", "Description", "Use Count");
   ast_cli(a->fd,"%d modules loaded\n", ast_update_module_list(modlist_modentry, like));
   climodentryfd = -1;
   ast_mutex_unlock(&climodentrylock);
   return CLI_SUCCESS;
}
#undef MODLIST_FORMAT
#undef MODLIST_FORMAT2

static char *handle_showcalls(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   struct timeval curtime = ast_tvnow();
   int showuptime, printsec;

   switch (cmd) {
   case CLI_INIT:
      e->command = "core show calls [uptime]";
      e->usage =
         "Usage: core show calls [uptime] [seconds]\n"
         "       Lists number of currently active calls and total number of calls\n"
         "       processed through PBX since last restart. If 'uptime' is specified\n"
         "       the system uptime is also displayed. If 'seconds' is specified in\n"
         "       addition to 'uptime', the system uptime is displayed in seconds.\n";
      return NULL;

   case CLI_GENERATE:
      if (a->pos != e->args)
         return NULL;
      return a->n == 0  ? ast_strdup("seconds") : NULL;
   }

   /* regular handler */
   if (a->argc >= e->args && !strcasecmp(a->argv[e->args-1],"uptime")) {
      showuptime = 1;

      if (a->argc == e->args+1 && !strcasecmp(a->argv[e->args],"seconds"))
         printsec = 1;
      else if (a->argc == e->args)
         printsec = 0;
      else
         return CLI_SHOWUSAGE;
   } else if (a->argc == e->args-1) {
      showuptime = 0;
      printsec = 0;
   } else
      return CLI_SHOWUSAGE;

   if (option_maxcalls) {
      ast_cli(a->fd, "%d of %d max active call%s (%5.2f%% of capacity)\n",
         ast_active_calls(), option_maxcalls, ESS(ast_active_calls()),
         ((double)ast_active_calls() / (double)option_maxcalls) * 100.0);
   } else {
      ast_cli(a->fd, "%d active call%s\n", ast_active_calls(), ESS(ast_active_calls()));
   }
   
   ast_cli(a->fd, "%d call%s processed\n", ast_processed_calls(), ESS(ast_processed_calls()));

   if (ast_startuptime.tv_sec && showuptime) {
      print_uptimestr(a->fd, ast_tvsub(curtime, ast_startuptime), "System uptime", printsec);
   }

   return RESULT_SUCCESS;
}

static char *handle_chanlist(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
#define FORMAT_STRING  "%-20.20s %-20.20s %-7.7s %-30.30s\n"
#define FORMAT_STRING2 "%-20.20s %-20.20s %-7.7s %-30.30s\n"
#define CONCISE_FORMAT_STRING  "%s!%s!%s!%d!%s!%s!%s!%s!%s!%d!%s!%s!%s\n"
#define VERBOSE_FORMAT_STRING  "%-20.20s %-20.20s %-16.16s %4d %-7.7s %-12.12s %-25.25s %-15.15s %8.8s %-11.11s %-20.20s\n"
#define VERBOSE_FORMAT_STRING2 "%-20.20s %-20.20s %-16.16s %-4.4s %-7.7s %-12.12s %-25.25s %-15.15s %8.8s %-11.11s %-20.20s\n"

   struct ast_channel *c = NULL;
   int numchans = 0, concise = 0, verbose = 0, count = 0;
   int fd, argc;
   char **argv;

   switch (cmd) {
   case CLI_INIT:
      e->command = "core show channels [concise|verbose|count]";
      e->usage =
         "Usage: core show channels [concise|verbose|count]\n"
         "       Lists currently defined channels and some information about them. If\n"
         "       'concise' is specified, the format is abridged and in a more easily\n"
         "       machine parsable format. If 'verbose' is specified, the output includes\n"
         "       more and longer fields. If 'count' is specified only the channel and call\n"
         "       count is output.\n"
         "  The 'concise' option is deprecated and will be removed from future versions\n"
         "  of Asterisk.\n";
      return NULL;

   case CLI_GENERATE:
      return NULL;
   }
   fd = a->fd;
   argc = a->argc;
   argv = a->argv;

   if (a->argc == e->args) {
      if (!strcasecmp(argv[e->args-1],"concise"))
         concise = 1;
      else if (!strcasecmp(argv[e->args-1],"verbose"))
         verbose = 1;
      else if (!strcasecmp(argv[e->args-1],"count"))
         count = 1;
      else
         return CLI_SHOWUSAGE;
   } else if (a->argc != e->args - 1)
      return CLI_SHOWUSAGE;

   if (!count) {
      if (!concise && !verbose)
         ast_cli(fd, FORMAT_STRING2, "Channel", "Location", "State", "Application(Data)");
      else if (verbose)
         ast_cli(fd, VERBOSE_FORMAT_STRING2, "Channel", "Context", "Extension", "Priority", "State", "Application", "Data", 
            "CallerID", "Duration", "Accountcode", "BridgedTo");
   }

   while ((c = ast_channel_walk_locked(c)) != NULL) {
      struct ast_channel *bc = ast_bridged_channel(c);
      char durbuf[10] = "-";

      if (!count) {
         if ((concise || verbose)  && c->cdr && !ast_tvzero(c->cdr->start)) {
            int duration = (int)(ast_tvdiff_ms(ast_tvnow(), c->cdr->start) / 1000);
            if (verbose) {
               int durh = duration / 3600;
               int durm = (duration % 3600) / 60;
               int durs = duration % 60;
               snprintf(durbuf, sizeof(durbuf), "%02d:%02d:%02d", durh, durm, durs);
            } else {
               snprintf(durbuf, sizeof(durbuf), "%d", duration);
            }           
         }
         if (concise) {
            ast_cli(fd, CONCISE_FORMAT_STRING, c->name, c->context, c->exten, c->priority, ast_state2str(c->_state),
               c->appl ? c->appl : "(None)",
               S_OR(c->data, ""),   /* XXX different from verbose ? */
               S_OR(c->cid.cid_num, ""),
               S_OR(c->accountcode, ""),
               c->amaflags, 
               durbuf,
               bc ? bc->name : "(None)",
               c->uniqueid);
         } else if (verbose) {
            ast_cli(fd, VERBOSE_FORMAT_STRING, c->name, c->context, c->exten, c->priority, ast_state2str(c->_state),
               c->appl ? c->appl : "(None)",
               c->data ? S_OR(c->data, "(Empty)" ): "(None)",
               S_OR(c->cid.cid_num, ""),
               durbuf,
               S_OR(c->accountcode, ""),
               bc ? bc->name : "(None)");
         } else {
            char locbuf[40] = "(None)";
            char appdata[40] = "(None)";
            
            if (!ast_strlen_zero(c->context) && !ast_strlen_zero(c->exten)) 
               snprintf(locbuf, sizeof(locbuf), "%s@%s:%d", c->exten, c->context, c->priority);
            if (c->appl)
               snprintf(appdata, sizeof(appdata), "%s(%s)", c->appl, S_OR(c->data, ""));
            ast_cli(fd, FORMAT_STRING, c->name, locbuf, ast_state2str(c->_state), appdata);
         }
      }
      numchans++;
      ast_channel_unlock(c);
   }
   if (!concise) {
      ast_cli(fd, "%d active channel%s\n", numchans, ESS(numchans));
      if (option_maxcalls)
         ast_cli(fd, "%d of %d max active call%s (%5.2f%% of capacity)\n",
            ast_active_calls(), option_maxcalls, ESS(ast_active_calls()),
            ((double)ast_active_calls() / (double)option_maxcalls) * 100.0);
      else
         ast_cli(fd, "%d active call%s\n", ast_active_calls(), ESS(ast_active_calls()));

      ast_cli(fd, "%d call%s processed\n", ast_processed_calls(), ESS(ast_processed_calls()));
   }
   return CLI_SUCCESS;
   
#undef FORMAT_STRING
#undef FORMAT_STRING2
#undef CONCISE_FORMAT_STRING
#undef VERBOSE_FORMAT_STRING
#undef VERBOSE_FORMAT_STRING2
}

static char *handle_softhangup(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   struct ast_channel *c=NULL;

   switch (cmd) {
   case CLI_INIT:
      e->command = "channel request hangup";
      e->usage =
         "Usage: channel request hangup <channel>\n"
         "       Request that a channel be hung up. The hangup takes effect\n"
         "       the next time the driver reads or writes from the channel\n";
      return NULL;
   case CLI_GENERATE:
      return ast_complete_channels(a->line, a->word, a->pos, a->n, e->args);
   }
   if (a->argc != 4)
      return CLI_SHOWUSAGE;
   c = ast_get_channel_by_name_locked(a->argv[3]);
   if (c) {
      ast_cli(a->fd, "Requested Hangup on channel '%s'\n", c->name);
      ast_softhangup(c, AST_SOFTHANGUP_EXPLICIT);
      ast_channel_unlock(c);
   } else
      ast_cli(a->fd, "%s is not a known channel\n", a->argv[3]);
   return CLI_SUCCESS;
}

/*! \brief handles CLI command 'cli show permissions' */
static char *handle_cli_show_permissions(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   struct usergroup_cli_perm *cp;
   struct cli_perm *perm;
   struct passwd *pw = NULL;
   struct group *gr = NULL;

   switch (cmd) {
   case CLI_INIT:
      e->command = "cli show permissions";
      e->usage =
         "Usage: cli show permissions\n"
         "       Shows CLI configured permissions.\n";
      return NULL;
   case CLI_GENERATE:
      return NULL;
   }

   AST_RWLIST_RDLOCK(&cli_perms);
   AST_LIST_TRAVERSE(&cli_perms, cp, list) {
      if (cp->uid >= 0) {
         pw = getpwuid(cp->uid);
         if (pw) {
            ast_cli(a->fd, "user: %s [uid=%d]\n", pw->pw_name, cp->uid);
         }
      } else {
         gr = getgrgid(cp->gid);
         if (gr) {
            ast_cli(a->fd, "group: %s [gid=%d]\n", gr->gr_name, cp->gid);
         }
      }
      ast_cli(a->fd, "Permissions:\n");
      if (cp->perms) {
         AST_LIST_TRAVERSE(cp->perms, perm, list) {
            ast_cli(a->fd, "\t%s -> %s\n", perm->permit ? "permit" : "deny", perm->command);
         }
      }
      ast_cli(a->fd, "\n");
   }
   AST_RWLIST_UNLOCK(&cli_perms);

   return CLI_SUCCESS;
}

/*! \brief handles CLI command 'cli reload permissions' */
static char *handle_cli_reload_permissions(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   switch (cmd) {
   case CLI_INIT:
      e->command = "cli reload permissions";
      e->usage =
         "Usage: cli reload permissions\n"
         "       Reload the 'cli_permissions.conf' file.\n";
      return NULL;
   case CLI_GENERATE:
      return NULL;
   }

   ast_cli_perms_init(1);

   return CLI_SUCCESS;
}

/*! \brief handles CLI command 'cli check permissions' */
static char *handle_cli_check_permissions(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   struct passwd *pw = NULL;
   struct group *gr;
   int gid = -1, uid = -1;
   char command[AST_MAX_ARGS] = "";
   struct ast_cli_entry *ce = NULL;
   int found = 0;
   char *group, *tmp;

   switch (cmd) {
   case CLI_INIT:
      e->command = "cli check permissions";
      e->usage =
         "Usage: cli check permissions {<username>|@<groupname>|<username>@<groupname>} [<command>]\n"
         "       Check permissions config for a user@group or list the allowed commands for the specified user.\n"
         "       The username or the groupname may be omitted.\n";
      return NULL;
   case CLI_GENERATE:
      if (a->pos >= 4) {
         return ast_cli_generator(a->line + strlen("cli check permissions") + strlen(a->argv[3]) + 1, a->word, a->n);
      }
      return NULL;
   }

   if (a->argc < 4) {
      return CLI_SHOWUSAGE;
   }

   tmp = ast_strdupa(a->argv[3]);
   group = strchr(tmp, '@');
   if (group) {
      gr = getgrnam(&group[1]);
      if (!gr) {
         ast_cli(a->fd, "Unknown group '%s'\n", &group[1]);
         return CLI_FAILURE;
      }
      group[0] = '\0';
      gid = gr->gr_gid;
   }

   if (!group && ast_strlen_zero(tmp)) {
      ast_cli(a->fd, "You didn't supply a username\n");
   } else if (!ast_strlen_zero(tmp) && !(pw = getpwnam(tmp))) {
      ast_cli(a->fd, "Unknown user '%s'\n", tmp);
      return CLI_FAILURE;
   } else if (pw) {
      uid = pw->pw_uid;
   }

   if (a->argc == 4) {
      while ((ce = cli_next(ce))) {
         /* Hide commands that start with '_' */
         if (ce->_full_cmd[0] == '_') {
            continue;
         }
         if (cli_has_permissions(uid, gid, ce->_full_cmd)) {
            ast_cli(a->fd, "%30.30s %s\n", ce->_full_cmd, S_OR(ce->summary, "<no description available>"));
            found++;
         }
      }
      if (!found) {
         ast_cli(a->fd, "You are not allowed to run any command on Asterisk\n");
      }
   } else {
      ast_join(command, sizeof(command), a->argv + 4);
      ast_cli(a->fd, "%s '%s%s%s' is %s to run command: '%s'\n", uid >= 0 ? "User" : "Group", tmp,
         group && uid >= 0 ? "@" : "",
         group ? &group[1] : "",
         cli_has_permissions(uid, gid, command) ? "allowed" : "not allowed", command);
   }

   return CLI_SUCCESS;
}

static char *__ast_cli_generator(const char *text, const char *word, int state, int lock);

static char *handle_commandmatchesarray(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   char *buf, *obuf;
   int buflen = 2048;
   int len = 0;
   char **matches;
   int x, matchlen;
   
   switch (cmd) {
   case CLI_INIT:
      e->command = "_command matchesarray";
      e->usage = 
         "Usage: _command matchesarray \"<line>\" text \n"
         "       This function is used internally to help with command completion and should.\n"
         "       never be called by the user directly.\n";
      return NULL;
   case CLI_GENERATE:
      return NULL;
   }

   if (a->argc != 4)
      return CLI_SHOWUSAGE;
   if (!(buf = ast_malloc(buflen)))
      return CLI_FAILURE;
   buf[len] = '\0';
   matches = ast_cli_completion_matches(a->argv[2], a->argv[3]);
   if (matches) {
      for (x=0; matches[x]; x++) {
         matchlen = strlen(matches[x]) + 1;
         if (len + matchlen >= buflen) {
            buflen += matchlen * 3;
            obuf = buf;
            if (!(buf = ast_realloc(obuf, buflen))) 
               /* Memory allocation failure...  Just free old buffer and be done */
               ast_free(obuf);
         }
         if (buf)
            len += sprintf( buf + len, "%s ", matches[x]);
         ast_free(matches[x]);
         matches[x] = NULL;
      }
      ast_free(matches);
   }

   if (buf) {
      ast_cli(a->fd, "%s%s",buf, AST_CLI_COMPLETE_EOF);
      ast_free(buf);
   } else
      ast_cli(a->fd, "NULL\n");

   return CLI_SUCCESS;
}



static char *handle_commandnummatches(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   int matches = 0;

   switch (cmd) {
   case CLI_INIT:
      e->command = "_command nummatches";
      e->usage = 
         "Usage: _command nummatches \"<line>\" text \n"
         "       This function is used internally to help with command completion and should.\n"
         "       never be called by the user directly.\n";
      return NULL;
   case CLI_GENERATE:
      return NULL;
   }

   if (a->argc != 4)
      return CLI_SHOWUSAGE;

   matches = ast_cli_generatornummatches(a->argv[2], a->argv[3]);

   ast_cli(a->fd, "%d", matches);

   return CLI_SUCCESS;
}

static char *handle_commandcomplete(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   char *buf;
   switch (cmd) {
   case CLI_INIT:
      e->command = "_command complete";
      e->usage = 
         "Usage: _command complete \"<line>\" text state\n"
         "       This function is used internally to help with command completion and should.\n"
         "       never be called by the user directly.\n";
      return NULL;
   case CLI_GENERATE:
      return NULL;
   }
   if (a->argc != 5)
      return CLI_SHOWUSAGE;
   buf = __ast_cli_generator(a->argv[2], a->argv[3], atoi(a->argv[4]), 0);
   if (buf) {
      ast_cli(a->fd, "%s", buf);
      ast_free(buf);
   } else
      ast_cli(a->fd, "NULL\n");
   return CLI_SUCCESS;
}

static char *handle_core_set_debug_channel(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   struct ast_channel *c = NULL;
   int is_all, is_off = 0;

   switch (cmd) {
   case CLI_INIT:
      e->command = "core set debug channel";
      e->usage =
         "Usage: core set debug channel <all|channel> [off]\n"
         "       Enables/disables debugging on all or on a specific channel.\n";
      return NULL;

   case CLI_GENERATE:
      /* XXX remember to handle the optional "off" */
      if (a->pos != e->args)
         return NULL;
      return a->n == 0 ? ast_strdup("all") : ast_complete_channels(a->line, a->word, a->pos, a->n - 1, e->args);
   }
   /* 'core set debug channel {all|chan_id}' */
   if (a->argc == e->args + 2) {
      if (!strcasecmp(a->argv[e->args + 1], "off"))
         is_off = 1;
      else
         return CLI_SHOWUSAGE;
   } else if (a->argc != e->args + 1)
      return CLI_SHOWUSAGE;

   is_all = !strcasecmp("all", a->argv[e->args]);
   if (is_all) {
      if (is_off) {
         global_fin &= ~DEBUGCHAN_FLAG;
         global_fout &= ~DEBUGCHAN_FLAG;
      } else {
         global_fin |= DEBUGCHAN_FLAG;
         global_fout |= DEBUGCHAN_FLAG;
      }
      c = ast_channel_walk_locked(NULL);
   } else {
      c = ast_get_channel_by_name_locked(a->argv[e->args]);
      if (c == NULL)
         ast_cli(a->fd, "No such channel %s\n", a->argv[e->args]);
   }
   while (c) {
      if (!(c->fin & DEBUGCHAN_FLAG) || !(c->fout & DEBUGCHAN_FLAG)) {
         if (is_off) {
            c->fin &= ~DEBUGCHAN_FLAG;
            c->fout &= ~DEBUGCHAN_FLAG;
         } else {
            c->fin |= DEBUGCHAN_FLAG;
            c->fout |= DEBUGCHAN_FLAG;
         }
         ast_cli(a->fd, "Debugging %s on channel %s\n", is_off ? "disabled" : "enabled", c->name);
      }
      ast_channel_unlock(c);
      if (!is_all)
         break;
      c = ast_channel_walk_locked(c);
   }
   ast_cli(a->fd, "Debugging on new channels is %s\n", is_off ? "disabled" : "enabled");
   return CLI_SUCCESS;
}

static char *handle_nodebugchan_deprecated(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   char *res;
   if (cmd == CLI_HANDLER) {
      if (a->argc != e->args + 1)
         return CLI_SHOWUSAGE;
      /* pretend we have an extra "off" at the end. We can do this as the array
       * is NULL terminated so we overwrite that entry.
       */
      a->argv[e->args+1] = "off";
      a->argc++;
   }
   res = handle_core_set_debug_channel(e, cmd, a);
   if (cmd == CLI_INIT)
      e->command = "no debug channel";
   return res;
}
      
static char *handle_showchan(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   struct ast_channel *c=NULL;
   struct timeval now;
   struct ast_str *out = ast_str_thread_get(&ast_str_thread_global_buf, 16);
   char cdrtime[256];
   char nf[256], wf[256], rf[256];
   long elapsed_seconds=0;
   int hour=0, min=0, sec=0;
#ifdef CHANNEL_TRACE
   int trace_enabled;
#endif

   switch (cmd) {
   case CLI_INIT:
      e->command = "core show channel";
      e->usage = 
         "Usage: core show channel <channel>\n"
         "       Shows lots of information about the specified channel.\n";
      return NULL;
   case CLI_GENERATE:
      return ast_complete_channels(a->line, a->word, a->pos, a->n, 3);
   }
   
   if (a->argc != 4)
      return CLI_SHOWUSAGE;
   now = ast_tvnow();
   c = ast_get_channel_by_name_locked(a->argv[3]);
   if (!c) {
      ast_cli(a->fd, "%s is not a known channel\n", a->argv[3]);
      return CLI_SUCCESS;
   }
   if (c->cdr) {
      elapsed_seconds = now.tv_sec - c->cdr->start.tv_sec;
      hour = elapsed_seconds / 3600;
      min = (elapsed_seconds % 3600) / 60;
      sec = elapsed_seconds % 60;
      snprintf(cdrtime, sizeof(cdrtime), "%dh%dm%ds", hour, min, sec);
   } else
      strcpy(cdrtime, "N/A");
   ast_cli(a->fd, 
      " -- General --\n"
      "           Name: %s\n"
      "           Type: %s\n"
      "       UniqueID: %s\n"
      "      Caller ID: %s\n"
      " Caller ID Name: %s\n"
      "    DNID Digits: %s\n"
      "       Language: %s\n"
      "          State: %s (%d)\n"
      "          Rings: %d\n"
      "  NativeFormats: %s\n"
      "    WriteFormat: %s\n"
      "     ReadFormat: %s\n"
      " WriteTranscode: %s\n"
      "  ReadTranscode: %s\n"
      "1st File Descriptor: %d\n"
      "      Frames in: %d%s\n"
      "     Frames out: %d%s\n"
      " Time to Hangup: %ld\n"
      "   Elapsed Time: %s\n"
      "  Direct Bridge: %s\n"
      "Indirect Bridge: %s\n"
      " --   PBX   --\n"
      "        Context: %s\n"
      "      Extension: %s\n"
      "       Priority: %d\n"
      "     Call Group: %llu\n"
      "   Pickup Group: %llu\n"
      "    Application: %s\n"
      "           Data: %s\n"
      "    Blocking in: %s\n",
      c->name, c->tech->type, c->uniqueid,
      S_OR(c->cid.cid_num, "(N/A)"),
      S_OR(c->cid.cid_name, "(N/A)"),
      S_OR(c->cid.cid_dnid, "(N/A)"), 
      c->language,   
      ast_state2str(c->_state), c->_state, c->rings, 
      ast_getformatname_multiple(nf, sizeof(nf), c->nativeformats), 
      ast_getformatname_multiple(wf, sizeof(wf), c->writeformat), 
      ast_getformatname_multiple(rf, sizeof(rf), c->readformat),
      c->writetrans ? "Yes" : "No",
      c->readtrans ? "Yes" : "No",
      c->fds[0],
      c->fin & ~DEBUGCHAN_FLAG, (c->fin & DEBUGCHAN_FLAG) ? " (DEBUGGED)" : "",
      c->fout & ~DEBUGCHAN_FLAG, (c->fout & DEBUGCHAN_FLAG) ? " (DEBUGGED)" : "",
      (long)c->whentohangup.tv_sec,
      cdrtime, c->_bridge ? c->_bridge->name : "<none>", ast_bridged_channel(c) ? ast_bridged_channel(c)->name : "<none>", 
      c->context, c->exten, c->priority, c->callgroup, c->pickupgroup, ( c->appl ? c->appl : "(N/A)" ),
      ( c-> data ? S_OR(c->data, "(Empty)") : "(None)"),
      (ast_test_flag(c, AST_FLAG_BLOCKING) ? c->blockproc : "(Not Blocking)"));
   
   if (pbx_builtin_serialize_variables(c, &out))
      ast_cli(a->fd,"      Variables:\n%s\n", ast_str_buffer(out));
   if (c->cdr && ast_cdr_serialize_variables(c->cdr, &out, '=', '\n', 1))
      ast_cli(a->fd,"  CDR Variables:\n%s\n", ast_str_buffer(out));
#ifdef CHANNEL_TRACE
   trace_enabled = ast_channel_trace_is_enabled(c);
   ast_cli(a->fd, "  Context Trace: %s\n", trace_enabled ? "Enabled" : "Disabled");
   if (trace_enabled && ast_channel_trace_serialize(c, &out))
      ast_cli(a->fd, "          Trace:\n%s\n", ast_str_buffer(out));
#endif
   ast_channel_unlock(c);
   return CLI_SUCCESS;
}

/*
 * helper function to generate CLI matches from a fixed set of values.
 * A NULL word is acceptable.
 */
char *ast_cli_complete(const char *word, char *const choices[], int state)
{
   int i, which = 0, len;
   len = ast_strlen_zero(word) ? 0 : strlen(word);

   for (i = 0; choices[i]; i++) {
      if ((!len || !strncasecmp(word, choices[i], len)) && ++which > state)
         return ast_strdup(choices[i]);
   }
   return NULL;
}

char *ast_complete_channels(const char *line, const char *word, int pos, int state, int rpos)
{
   struct ast_channel *c = NULL;
   int which = 0;
   int wordlen;
   char notfound = '\0';
   char *ret = &notfound; /* so NULL can break the loop */

   if (pos != rpos)
      return NULL;

   wordlen = strlen(word); 

   while (ret == &notfound && (c = ast_channel_walk_locked(c))) {
      if (!strncasecmp(word, c->name, wordlen) && ++which > state)
         ret = ast_strdup(c->name);
      ast_channel_unlock(c);
   }
   return ret == &notfound ? NULL : ret;
}

static char *group_show_channels(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
#define FORMAT_STRING  "%-25s  %-20s  %-20s\n"

   struct ast_group_info *gi = NULL;
   int numchans = 0;
   regex_t regexbuf;
   int havepattern = 0;

   switch (cmd) {
   case CLI_INIT:
      e->command = "group show channels";
      e->usage = 
         "Usage: group show channels [pattern]\n"
         "       Lists all currently active channels with channel group(s) specified.\n"
         "       Optional regular expression pattern is matched to group names for each\n"
         "       channel.\n";
      return NULL;
   case CLI_GENERATE:
      return NULL;
   }

   if (a->argc < 3 || a->argc > 4)
      return CLI_SHOWUSAGE;
   
   if (a->argc == 4) {
      if (regcomp(&regexbuf, a->argv[3], REG_EXTENDED | REG_NOSUB))
         return CLI_SHOWUSAGE;
      havepattern = 1;
   }

   ast_cli(a->fd, FORMAT_STRING, "Channel", "Group", "Category");

   ast_app_group_list_rdlock();
   
   gi = ast_app_group_list_head();
   while (gi) {
      if (!havepattern || !regexec(&regexbuf, gi->group, 0, NULL, 0)) {
         ast_cli(a->fd, FORMAT_STRING, gi->chan->name, gi->group, (ast_strlen_zero(gi->category) ? "(default)" : gi->category));
         numchans++;
      }
      gi = AST_LIST_NEXT(gi, group_list);
   }
   
   ast_app_group_list_unlock();
   
   if (havepattern)
      regfree(&regexbuf);

   ast_cli(a->fd, "%d active channel%s\n", numchans, ESS(numchans));
   return CLI_SUCCESS;
#undef FORMAT_STRING
}

static char *handle_help(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a);

static struct ast_cli_entry cli_cli[] = {
   /* Deprecated, but preferred command is now consolidated (and already has a deprecated command for it). */
   AST_CLI_DEFINE(handle_commandcomplete, "Command complete"),
   AST_CLI_DEFINE(handle_commandnummatches, "Returns number of command matches"),
   AST_CLI_DEFINE(handle_commandmatchesarray, "Returns command matches array"),

   AST_CLI_DEFINE(handle_nodebugchan_deprecated, "Disable debugging on channel(s)"),

   AST_CLI_DEFINE(handle_chanlist, "Display information on channels"),

   AST_CLI_DEFINE(handle_showcalls, "Display information on calls"),

   AST_CLI_DEFINE(handle_showchan, "Display information on a specific channel"),

   AST_CLI_DEFINE(handle_core_set_debug_channel, "Enable/disable debugging on a channel"),

   AST_CLI_DEFINE(handle_verbose, "Set level of debug/verbose chattiness"),

   AST_CLI_DEFINE(group_show_channels, "Display active channels with group(s)"),

   AST_CLI_DEFINE(handle_help, "Display help list, or specific help on a command"),

   AST_CLI_DEFINE(handle_logger_mute, "Toggle logging output to a console"),

   AST_CLI_DEFINE(handle_modlist, "List modules and info"),

   AST_CLI_DEFINE(handle_load, "Load a module by name"),

   AST_CLI_DEFINE(handle_reload, "Reload configuration"),

   AST_CLI_DEFINE(handle_unload, "Unload a module by name"),

   AST_CLI_DEFINE(handle_showuptime, "Show uptime information"),

   AST_CLI_DEFINE(handle_softhangup, "Request a hangup on a given channel"),

   AST_CLI_DEFINE(handle_cli_reload_permissions, "Reload CLI permissions config"),

   AST_CLI_DEFINE(handle_cli_show_permissions, "Show CLI permissions"),

   AST_CLI_DEFINE(handle_cli_check_permissions, "Try a permissions config for a user"),
};

/*!
 * Some regexp characters in cli arguments are reserved and used as separators.
 */
static const char cli_rsvd[] = "[]{}|*%";

/*!
 * initialize the _full_cmd string and related parameters,
 * return 0 on success, -1 on error.
 */
static int set_full_cmd(struct ast_cli_entry *e)
{
   int i;
   char buf[80];

   ast_join(buf, sizeof(buf), e->cmda);
   e->_full_cmd = ast_strdup(buf);
   if (!e->_full_cmd) {
      ast_log(LOG_WARNING, "-- cannot allocate <%s>\n", buf);
      return -1;
   }
   e->cmdlen = strcspn(e->_full_cmd, cli_rsvd);
   for (i = 0; e->cmda[i]; i++)
      ;
   e->args = i;
   return 0;
}

/*! \brief cleanup (free) cli_perms linkedlist. */
static void destroy_user_perms(void)
{
   struct cli_perm *perm;
   struct usergroup_cli_perm *user_perm;

   AST_RWLIST_WRLOCK(&cli_perms);
   while ((user_perm = AST_LIST_REMOVE_HEAD(&cli_perms, list))) {
      while ((perm = AST_LIST_REMOVE_HEAD(user_perm->perms, list))) {
         ast_free(perm->command);
         ast_free(perm);
      }
      ast_free(user_perm);
   }
   AST_RWLIST_UNLOCK(&cli_perms);
}

int ast_cli_perms_init(int reload)
{
   struct ast_flags config_flags = { reload ? CONFIG_FLAG_FILEUNCHANGED : 0 };
   struct ast_config *cfg;
   char *cat = NULL;
   struct ast_variable *v;
   struct usergroup_cli_perm *user_group, *cp_entry;
   struct cli_perm *perm = NULL;
   struct passwd *pw;
   struct group *gr;

   if (ast_mutex_trylock(&permsconfiglock)) {
      ast_log(LOG_NOTICE, "You must wait until last 'cli reload permissions' command finish\n");
      return 1;
   }

   cfg = ast_config_load2(perms_config, "" /* core, can't reload */, config_flags);
   if (!cfg) {
      ast_mutex_unlock(&permsconfiglock);
      return 1;
   } else if (cfg == CONFIG_STATUS_FILEUNCHANGED) {
      ast_mutex_unlock(&permsconfiglock);
      return 0;
   }

   /* free current structures. */
   destroy_user_perms();

   while ((cat = ast_category_browse(cfg, cat))) {
      if (!strcasecmp(cat, "general")) {
         /* General options */
         for (v = ast_variable_browse(cfg, cat); v; v = v->next) {
            if (!strcasecmp(v->name, "default_perm")) {
               cli_default_perm = (!strcasecmp(v->value, "permit")) ? 1: 0;
            }
         }
         continue;
      }

      /* users or groups */
      gr = NULL, pw = NULL;
      if (cat[0] == '@') {
         /* This is a group */
         gr = getgrnam(&cat[1]);
         if (!gr) {
            ast_log (LOG_WARNING, "Unknown group '%s'\n", &cat[1]);
            continue;
         }
      } else {
         /* This is a user */
         pw = getpwnam(cat);
         if (!pw) {
            ast_log (LOG_WARNING, "Unknown user '%s'\n", cat);
            continue;
         }
      }
      user_group = NULL;
      /* Check for duplicates */
      AST_RWLIST_WRLOCK(&cli_perms);
      AST_LIST_TRAVERSE(&cli_perms, cp_entry, list) {
         if ((pw && cp_entry->uid == pw->pw_uid) || (gr && cp_entry->gid == gr->gr_gid)) {
            /* if it is duplicated, just added this new settings, to 
            the current list. */
            user_group = cp_entry;
            break;
         }
      }
      AST_RWLIST_UNLOCK(&cli_perms);

      if (!user_group) {
         /* alloc space for the new user config. */
         user_group = ast_calloc(1, sizeof(*user_group));
         if (!user_group) {
            continue;
         }
         user_group->uid = (pw ? pw->pw_uid : -1);
         user_group->gid = (gr ? gr->gr_gid : -1);
         user_group->perms = ast_calloc(1, sizeof(*user_group->perms));
         if (!user_group->perms) {
            ast_free(user_group);
            continue;
         }
      }
      for (v = ast_variable_browse(cfg, cat); v; v = v->next) {
         if (ast_strlen_zero(v->value)) {
            /* we need to check this condition cause it could break security. */
            ast_log(LOG_WARNING, "Empty permit/deny option in user '%s'\n", cat);
            continue;
         }
         if (!strcasecmp(v->name, "permit")) {
            perm = ast_calloc(1, sizeof(*perm));
            if (perm) {
               perm->permit = 1;
               perm->command = ast_strdup(v->value);
            }
         } else if (!strcasecmp(v->name, "deny")) {
            perm = ast_calloc(1, sizeof(*perm));
            if (perm) {
               perm->permit = 0;
               perm->command = ast_strdup(v->value);
            }
         } else {
            /* up to now, only 'permit' and 'deny' are possible values. */
            ast_log(LOG_WARNING, "Unknown '%s' option\n", v->name);
            continue;
         }
         if (perm) {
            /* Added the permission to the user's list. */
            AST_LIST_INSERT_TAIL(user_group->perms, perm, list);
            perm = NULL;
         }
      }
      AST_RWLIST_WRLOCK(&cli_perms);
      AST_RWLIST_INSERT_TAIL(&cli_perms, user_group, list);
      AST_RWLIST_UNLOCK(&cli_perms);
   }

   ast_config_destroy(cfg);
   ast_mutex_unlock(&permsconfiglock);
   return 0;
}

/*! \brief initialize the _full_cmd string in * each of the builtins. */
void ast_builtins_init(void)
{
   ast_cli_register_multiple(cli_cli, ARRAY_LEN(cli_cli));
}

/*!
 * match a word in the CLI entry.
 * returns -1 on mismatch, 0 on match of an optional word,
 * 1 on match of a full word.
 *
 * The pattern can be
 *   any_word           match for equal
 *   [foo|bar|baz]      optionally, one of these words
 *   {foo|bar|baz}      exactly, one of these words
 *   %                  any word
 */
static int word_match(const char *cmd, const char *cli_word)
{
   int l;
   char *pos;

   if (ast_strlen_zero(cmd) || ast_strlen_zero(cli_word))
      return -1;
   if (!strchr(cli_rsvd, cli_word[0])) /* normal match */
      return (strcasecmp(cmd, cli_word) == 0) ? 1 : -1;
   /* regexp match, takes [foo|bar] or {foo|bar} */
   l = strlen(cmd);
   /* wildcard match - will extend in the future */
   if (l > 0 && cli_word[0] == '%') {
      return 1;   /* wildcard */
   }
   pos = strcasestr(cli_word, cmd);
   if (pos == NULL) /* not found, say ok if optional */
      return cli_word[0] == '[' ? 0 : -1;
   if (pos == cli_word) /* no valid match at the beginning */
      return -1;
   if (strchr(cli_rsvd, pos[-1]) && strchr(cli_rsvd, pos[l]))
      return 1;   /* valid match */
   return -1;  /* not found */
}

/*! \brief if word is a valid prefix for token, returns the pos-th
 * match as a malloced string, or NULL otherwise.
 * Always tell in *actual how many matches we got.
 */
static char *is_prefix(const char *word, const char *token,
   int pos, int *actual)
{
   int lw;
   char *s, *t1;

   *actual = 0;
   if (ast_strlen_zero(token))
      return NULL;
   if (ast_strlen_zero(word))
      word = "";  /* dummy */
   lw = strlen(word);
   if (strcspn(word, cli_rsvd) != lw)
      return NULL;   /* no match if word has reserved chars */
   if (strchr(cli_rsvd, token[0]) == NULL) { /* regular match */
      if (strncasecmp(token, word, lw))   /* no match */
         return NULL;
      *actual = 1;
      return (pos != 0) ? NULL : ast_strdup(token);
   }
   /* now handle regexp match */

   /* Wildcard always matches, so we never do is_prefix on them */

   t1 = ast_strdupa(token + 1);  /* copy, skipping first char */
   while (pos >= 0 && (s = strsep(&t1, cli_rsvd)) && *s) {
      if (*s == '%') /* wildcard */
         continue;
      if (strncasecmp(s, word, lw)) /* no match */
         continue;
      (*actual)++;
      if (pos-- == 0)
         return ast_strdup(s);
   }
   return NULL;
}

/*!
 * \internal
 * \brief locate a cli command in the 'helpers' list (which must be locked).
 *     The search compares word by word taking care of regexps in e->cmda
 *     This function will return NULL when nothing is matched, or the ast_cli_entry that matched.
 * \param cmds
 * \param match_type has 3 possible values:
 *      0       returns if the search key is equal or longer than the entry.
 *                note that trailing optional arguments are skipped.
 *      -1      true if the mismatch is on the last word XXX not true!
 *      1       true only on complete, exact match.
 *
 */
static struct ast_cli_entry *find_cli(char *const cmds[], int match_type)
{
   int matchlen = -1;   /* length of longest match so far */
   struct ast_cli_entry *cand = NULL, *e=NULL;

   while ( (e = cli_next(e)) ) {
      /* word-by word regexp comparison */
      char * const *src = cmds;
      char * const *dst = e->cmda;
      int n = 0;
      for (;; dst++, src += n) {
         n = word_match(*src, *dst);
         if (n < 0)
            break;
      }
      if (ast_strlen_zero(*dst) || ((*dst)[0] == '[' && ast_strlen_zero(dst[1]))) {
         /* no more words in 'e' */
         if (ast_strlen_zero(*src)) /* exact match, cannot do better */
            break;
         /* Here, cmds has more words than the entry 'e' */
         if (match_type != 0) /* but we look for almost exact match... */
            continue;   /* so we skip this one. */
         /* otherwise we like it (case 0) */
      } else { /* still words in 'e' */
         if (ast_strlen_zero(*src))
            continue; /* cmds is shorter than 'e', not good */
         /* Here we have leftover words in cmds and 'e',
          * but there is a mismatch. We only accept this one if match_type == -1
          * and this is the last word for both.
          */
         if (match_type != -1 || !ast_strlen_zero(src[1]) ||
             !ast_strlen_zero(dst[1])) /* not the one we look for */
            continue;
         /* good, we are in case match_type == -1 and mismatch on last word */
      }
      if (src - cmds > matchlen) {  /* remember the candidate */
         matchlen = src - cmds;
         cand = e;
      }
   }

   return e ? e : cand;
}

static char *find_best(char *argv[])
{
   static char cmdline[80];
   int x;
   /* See how close we get, then print the candidate */
   char *myargv[AST_MAX_CMD_LEN];
   for (x=0;x<AST_MAX_CMD_LEN;x++)
      myargv[x]=NULL;
   AST_RWLIST_RDLOCK(&helpers);
   for (x=0;argv[x];x++) {
      myargv[x] = argv[x];
      if (!find_cli(myargv, -1))
         break;
   }
   AST_RWLIST_UNLOCK(&helpers);
   ast_join(cmdline, sizeof(cmdline), myargv);
   return cmdline;
}

static int __ast_cli_unregister(struct ast_cli_entry *e, struct ast_cli_entry *ed)
{
   if (e->inuse) {
      ast_log(LOG_WARNING, "Can't remove command that is in use\n");
   } else {
      AST_RWLIST_WRLOCK(&helpers);
      AST_RWLIST_REMOVE(&helpers, e, list);
      AST_RWLIST_UNLOCK(&helpers);
      ast_free(e->_full_cmd);
      e->_full_cmd = NULL;
      if (e->handler) {
         /* this is a new-style entry. Reset fields and free memory. */
         char *cmda = (char *) e->cmda;
         memset(cmda, '\0', sizeof(e->cmda));
         ast_free(e->command);
         e->command = NULL;
         e->usage = NULL;
      }
   }
   return 0;
}

static int __ast_cli_register(struct ast_cli_entry *e, struct ast_cli_entry *ed)
{
   struct ast_cli_entry *cur;
   int i, lf, ret = -1;

   struct ast_cli_args a;  /* fake argument */
   char **dst = (char **)e->cmda;   /* need to cast as the entry is readonly */
   char *s;

   memset(&a, '\0', sizeof(a));
   e->handler(e, CLI_INIT, &a);
   /* XXX check that usage and command are filled up */
   s = ast_skip_blanks(e->command);
   s = e->command = ast_strdup(s);
   for (i=0; !ast_strlen_zero(s) && i < AST_MAX_CMD_LEN-1; i++) {
      *dst++ = s; /* store string */
      s = ast_skip_nonblanks(s);
      if (*s == '\0')   /* we are done */
         break;
      *s++ = '\0';
      s = ast_skip_blanks(s);
   }
   *dst++ = NULL;
   
   AST_RWLIST_WRLOCK(&helpers);
   
   if (find_cli(e->cmda, 1)) {
      ast_log(LOG_WARNING, "Command '%s' already registered (or something close enough)\n", S_OR(e->_full_cmd, e->command));
      goto done;
   }
   if (set_full_cmd(e))
      goto done;

   lf = e->cmdlen;
   AST_RWLIST_TRAVERSE_SAFE_BEGIN(&helpers, cur, list) {
      int len = cur->cmdlen;
      if (lf < len)
         len = lf;
      if (strncasecmp(e->_full_cmd, cur->_full_cmd, len) < 0) {
         AST_RWLIST_INSERT_BEFORE_CURRENT(e, list); 
         break;
      }
   }
   AST_RWLIST_TRAVERSE_SAFE_END;

   if (!cur)
      AST_RWLIST_INSERT_TAIL(&helpers, e, list); 
   ret = 0; /* success */

done:
   AST_RWLIST_UNLOCK(&helpers);

   return ret;
}

/* wrapper function, so we can unregister deprecated commands recursively */
int ast_cli_unregister(struct ast_cli_entry *e)
{
   return __ast_cli_unregister(e, NULL);
}

/* wrapper function, so we can register deprecated commands recursively */
int ast_cli_register(struct ast_cli_entry *e)
{
   return __ast_cli_register(e, NULL);
}

/*
 * register/unregister an array of entries.
 */
int ast_cli_register_multiple(struct ast_cli_entry *e, int len)
{
   int i, res = 0;

   for (i = 0; i < len; i++)
      res |= ast_cli_register(e + i);

   return res;
}

int ast_cli_unregister_multiple(struct ast_cli_entry *e, int len)
{
   int i, res = 0;

   for (i = 0; i < len; i++)
      res |= ast_cli_unregister(e + i);

   return res;
}


/*! \brief helper for final part of handle_help
 *  if locked = 1, assume the list is already locked
 */
static char *help1(int fd, char *match[], int locked)
{
   char matchstr[80] = "";
   struct ast_cli_entry *e = NULL;
   int len = 0;
   int found = 0;

   if (match) {
      ast_join(matchstr, sizeof(matchstr), match);
      len = strlen(matchstr);
   }
   if (!locked)
      AST_RWLIST_RDLOCK(&helpers);
   while ( (e = cli_next(e)) ) {
      /* Hide commands that start with '_' */
      if (e->_full_cmd[0] == '_')
         continue;
      if (match && strncasecmp(matchstr, e->_full_cmd, len))
         continue;
      ast_cli(fd, "%30.30s %s\n", e->_full_cmd, S_OR(e->summary, "<no description available>"));
      found++;
   }
   if (!locked)
      AST_RWLIST_UNLOCK(&helpers);
   if (!found && matchstr[0])
      ast_cli(fd, "No such command '%s'.\n", matchstr);
   return CLI_SUCCESS;
}

static char *handle_help(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   char fullcmd[80];
   struct ast_cli_entry *my_e;
   char *res = CLI_SUCCESS;

   if (cmd == CLI_INIT) {
      e->command = "core show help";
      e->usage =
         "Usage: core show help [topic]\n"
         "       When called with a topic as an argument, displays usage\n"
         "       information on the given command. If called without a\n"
         "       topic, it provides a list of commands.\n";
      return NULL;

   } else if (cmd == CLI_GENERATE) {
      /* skip first 14 or 15 chars, "core show help " */
      int l = strlen(a->line);

      if (l > 15) {
         l = 15;
      }
      /* XXX watch out, should stop to the non-generator parts */
      return __ast_cli_generator(a->line + l, a->word, a->n, 0);
   }
   if (a->argc == e->args) {
      return help1(a->fd, NULL, 0);
   }

   AST_RWLIST_RDLOCK(&helpers);
   my_e = find_cli(a->argv + 3, 1); /* try exact match first */
   if (!my_e) {
      res = help1(a->fd, a->argv + 3, 1 /* locked */);
      AST_RWLIST_UNLOCK(&helpers);
      return res;
   }
   if (my_e->usage)
      ast_cli(a->fd, "%s", my_e->usage);
   else {
      ast_join(fullcmd, sizeof(fullcmd), a->argv + 3);
      ast_cli(a->fd, "No help text available for '%s'.\n", fullcmd);
   }
   AST_RWLIST_UNLOCK(&helpers);
   return res;
}

static char *parse_args(const char *s, int *argc, char *argv[], int max, int *trailingwhitespace)
{
   char *duplicate, *cur;
   int x = 0;
   int quoted = 0;
   int escaped = 0;
   int whitespace = 1;
   int dummy = 0;

   if (trailingwhitespace == NULL)
      trailingwhitespace = &dummy;
   *trailingwhitespace = 0;
   if (s == NULL) /* invalid, though! */
      return NULL;
   /* make a copy to store the parsed string */
   if (!(duplicate = ast_strdup(s)))
      return NULL;

   cur = duplicate;
   /* scan the original string copying into cur when needed */
   for (; *s ; s++) {
      if (x >= max - 1) {
         ast_log(LOG_WARNING, "Too many arguments, truncating at %s\n", s);
         break;
      }
      if (*s == '"' && !escaped) {
         quoted = !quoted;
         if (quoted && whitespace) {
            /* start a quoted string from previous whitespace: new argument */
            argv[x++] = cur;
            whitespace = 0;
         }
      } else if ((*s == ' ' || *s == '\t') && !(quoted || escaped)) {
         /* If we are not already in whitespace, and not in a quoted string or
            processing an escape sequence, and just entered whitespace, then
            finalize the previous argument and remember that we are in whitespace
         */
         if (!whitespace) {
            *cur++ = '\0';
            whitespace = 1;
         }
      } else if (*s == '\\' && !escaped) {
         escaped = 1;
      } else {
         if (whitespace) {
            /* we leave whitespace, and are not quoted. So it's a new argument */
            argv[x++] = cur;
            whitespace = 0;
         }
         *cur++ = *s;
         escaped = 0;
      }
   }
   /* Null terminate */
   *cur++ = '\0';
   /* XXX put a NULL in the last argument, because some functions that take
    * the array may want a null-terminated array.
    * argc still reflects the number of non-NULL entries.
    */
   argv[x] = NULL;
   *argc = x;
   *trailingwhitespace = whitespace;
   return duplicate;
}

/*! \brief Return the number of unique matches for the generator */
int ast_cli_generatornummatches(const char *text, const char *word)
{
   int matches = 0, i = 0;
   char *buf = NULL, *oldbuf = NULL;

   while ((buf = ast_cli_generator(text, word, i++))) {
      if (!oldbuf || strcmp(buf,oldbuf))
         matches++;
      if (oldbuf)
         ast_free(oldbuf);
      oldbuf = buf;
   }
   if (oldbuf)
      ast_free(oldbuf);
   return matches;
}

char **ast_cli_completion_matches(const char *text, const char *word)
{
   char **match_list = NULL, *retstr, *prevstr;
   size_t match_list_len, max_equal, which, i;
   int matches = 0;

   /* leave entry 0 free for the longest common substring */
   match_list_len = 1;
   while ((retstr = ast_cli_generator(text, word, matches)) != NULL) {
      if (matches + 1 >= match_list_len) {
         match_list_len <<= 1;
         if (!(match_list = ast_realloc(match_list, match_list_len * sizeof(*match_list))))
            return NULL;
      }
      match_list[++matches] = retstr;
   }

   if (!match_list)
      return match_list; /* NULL */

   /* Find the longest substring that is common to all results
    * (it is a candidate for completion), and store a copy in entry 0.
    */
   prevstr = match_list[1];
   max_equal = strlen(prevstr);
   for (which = 2; which <= matches; which++) {
      for (i = 0; i < max_equal && toupper(prevstr[i]) == toupper(match_list[which][i]); i++)
         continue;
      max_equal = i;
   }

   if (!(retstr = ast_malloc(max_equal + 1)))
      return NULL;
   
   ast_copy_string(retstr, match_list[1], max_equal + 1);
   match_list[0] = retstr;

   /* ensure that the array is NULL terminated */
   if (matches + 1 >= match_list_len) {
      if (!(match_list = ast_realloc(match_list, (match_list_len + 1) * sizeof(*match_list))))
         return NULL;
   }
   match_list[matches + 1] = NULL;

   return match_list;
}

/*! \brief returns true if there are more words to match */
static int more_words (char * const *dst)
{
   int i;
   for (i = 0; dst[i]; i++) {
      if (dst[i][0] != '[')
         return -1;
   }
   return 0;
}
   
/*
 * generate the entry at position 'state'
 */
static char *__ast_cli_generator(const char *text, const char *word, int state, int lock)
{
   char *argv[AST_MAX_ARGS];
   struct ast_cli_entry *e = NULL;
   int x = 0, argindex, matchlen;
   int matchnum=0;
   char *ret = NULL;
   char matchstr[80] = "";
   int tws = 0;
   /* Split the argument into an array of words */
   char *duplicate = parse_args(text, &x, argv, ARRAY_LEN(argv), &tws);

   if (!duplicate)   /* malloc error */
      return NULL;

   /* Compute the index of the last argument (could be an empty string) */
   argindex = (!ast_strlen_zero(word) && x>0) ? x-1 : x;

   /* rebuild the command, ignore terminating white space and flatten space */
   ast_join(matchstr, sizeof(matchstr)-1, argv);
   matchlen = strlen(matchstr);
   if (tws) {
      strcat(matchstr, " "); /* XXX */
      if (matchlen)
         matchlen++;
   }
   if (lock)
      AST_RWLIST_RDLOCK(&helpers);
   while ( (e = cli_next(e)) ) {
      /* XXX repeated code */
      int src = 0, dst = 0, n = 0;

      if (e->command[0] == '_')
         continue;

      /*
       * Try to match words, up to and excluding the last word, which
       * is either a blank or something that we want to extend.
       */
      for (;src < argindex; dst++, src += n) {
         n = word_match(argv[src], e->cmda[dst]);
         if (n < 0)
            break;
      }

      if (src != argindex && more_words(e->cmda + dst))  /* not a match */
         continue;
      ret = is_prefix(argv[src], e->cmda[dst], state - matchnum, &n);
      matchnum += n; /* this many matches here */
      if (ret) {
         /*
          * argv[src] is a valid prefix of the next word in this
          * command. If this is also the correct entry, return it.
          */
         if (matchnum > state)
            break;
         ast_free(ret);
         ret = NULL;
      } else if (ast_strlen_zero(e->cmda[dst])) {
         /*
          * This entry is a prefix of the command string entered
          * (only one entry in the list should have this property).
          * Run the generator if one is available. In any case we are done.
          */
         if (e->handler) { /* new style command */
            struct ast_cli_args a = {
               .line = matchstr, .word = word,
               .pos = argindex,
               .n = state - matchnum,
               .argv = argv,
               .argc = x};
            ret = e->handler(e, CLI_GENERATE, &a);
         }
         if (ret)
            break;
      }
   }
   if (lock)
      AST_RWLIST_UNLOCK(&helpers);
   ast_free(duplicate);
   return ret;
}

char *ast_cli_generator(const char *text, const char *word, int state)
{
   return __ast_cli_generator(text, word, state, 1);
}

int ast_cli_command_full(int uid, int gid, int fd, const char *s)
{
   char *args[AST_MAX_ARGS + 1];
   struct ast_cli_entry *e;
   int x;
   char *duplicate = parse_args(s, &x, args + 1, AST_MAX_ARGS, NULL);
   char tmp[AST_MAX_ARGS + 1];
   char *retval = NULL;
   struct ast_cli_args a = {
      .fd = fd, .argc = x, .argv = args+1 };

   if (duplicate == NULL)
      return -1;

   if (x < 1)  /* We need at least one entry, otherwise ignore */
      goto done;

   AST_RWLIST_RDLOCK(&helpers);
   e = find_cli(args + 1, 0);
   if (e)
      ast_atomic_fetchadd_int(&e->inuse, 1);
   AST_RWLIST_UNLOCK(&helpers);
   if (e == NULL) {
      ast_cli(fd, "No such command '%s' (type 'core show help %s' for other possible commands)\n", s, find_best(args + 1));
      goto done;
   }

   ast_join(tmp, sizeof(tmp), args + 1);
   /* Check if the user has rights to run this command. */
   if (!cli_has_permissions(uid, gid, tmp)) {
      ast_cli(fd, "You don't have permissions to run '%s' command\n", tmp);
      ast_free(duplicate);
      return 0;
   }

   /*
    * Within the handler, argv[-1] contains a pointer to the ast_cli_entry.
    * Remember that the array returned by parse_args is NULL-terminated.
    */
   args[0] = (char *)e;

   retval = e->handler(e, CLI_HANDLER, &a);

   if (retval == CLI_SHOWUSAGE) {
      ast_cli(fd, "%s", S_OR(e->usage, "Invalid usage, but no usage information available.\n"));
   } else {
      if (retval == CLI_FAILURE)
         ast_cli(fd, "Command '%s' failed.\n", s);
   }
   ast_atomic_fetchadd_int(&e->inuse, -1);
done:
   ast_free(duplicate);
   return 0;
}

int ast_cli_command_multiple_full(int uid, int gid, int fd, size_t size, const char *s)
{
   char cmd[512];
   int x, y = 0, count = 0;

   for (x = 0; x < size; x++) {
      cmd[y] = s[x];
      y++;
      if (s[x] == '\0') {
         ast_cli_command_full(uid, gid, fd, cmd);
         y = 0;
         count++;
      }
   }
   return count;
}