const char *z = aCommand[i].zName;
    if( (aCommand[i].eCmdFlags & cmdMask)==0 ) continue;
    if( zPrefix && memcmp(zPrefix, z, nPrefix)!=0 ) continue;
    aCmd[nCmd++] = aCommand[i].zName;
  }
  multi_column_list(aCmd, nCmd);
}

/*
** Documentation on universal command-line options.
*/
/* @-comment: # */
static const char zOptions[] =
@ Command-line options common to all commands:
@ 
@   --args FILENAME         Read additional arguments and options from FILENAME
@   --cgitrace              Active CGI tracing
@   --comfmtflags VALUE     Set comment formatting flags to VALUE
@   --errorlog FILENAME     Log errors to FILENAME 
@   --help                  Show help on the command rather than running it
@   --httptrace             Trace outbound HTTP requests
@   --localtime             Display times using the local timezone
@   --no-th-hook            Do not run TH1 hooks
@   --quiet                 Reduce the amount of output
@   --sqlstats              Show SQL usage statistics when done
@   --sqltrace              Trace all SQL commands
@   --sshtrace              Trace SSH activity
@   --ssl-identity NAME     Set the SSL identity to NAME
@   --systemtrace           Trace calls to system()
@   --user|-U USER          Make the default user be USER
@   --utc                   Display times using UTC
@   --vfs NAME              Cause SQLite to use the NAME VFS
;

/*
** COMMAND: help
**
** Usage: %fossil help TOPIC
**    or: %fossil TOPIC --help
**
** Display information on how to use TOPIC, which may be a command, webpage, or
** setting.  Webpage names begin with "/".  To display a list of available
** topics, use one of:
**
**    %fossil help                Show common commands
**    %fossil help -a|--all       Show both common and auxiliary commands
**    %fossil help -o|--options   Show command-line options common to all cmds
**    %fossil help -s|--setting   Show setting names
**    %fossil help -t|--test      Show test commands only
**    %fossil help -x|--aux       Show auxiliary commands only
**    %fossil help -w|--www       Show list of webpages
*/
void help_cmd(void){
  int rc;
  int isPage = 0;
  const char *z;
  const char *zCmdOrPage;
  const char *zCmdOrPagePlural;
  const CmdOrPage *pCmd = 0;
  if( g.argc<3 ){
    z = g.argv[0];
    fossil_print(
      "Usage: %s help TOPIC\n"
      "Common commands:  (use \"%s help help\" for more options)\n",
      z, z);
    command_list(0, CMDFLAG_1ST_TIER);
    version_cmd();
    return;
  }
  if( find_option("options","o",0) ){
    fossil_print("%s", zOptions);
    return;
  }
  if( find_option("all","a",0) ){
    command_list(0, CMDFLAG_1ST_TIER | CMDFLAG_2ND_TIER);
    return;
  }
  else if( find_option("www","w",0) ){
    command_list(0, CMDFLAG_WEBPAGE);