ftp-srv-esm/src/commands/registration/help.js

Modern, extensible FTP server (daemon) for Node.js with ESM support. Based on ftp-srv.

let registryRef;

const help = {
  directive: 'HELP',
  handler: function ({command} = {}) {
    const directive = (command.arg || '').toUpperCase();
    if (directive) {
      if (!Object.prototype.hasOwnProperty.call(registryRef, directive)) return this.reply(502, `Unknown command ${directive}.`);

      const {syntax, description} = registryRef[directive];
      const reply = [syntax.replace('{{cmd}}', directive), description];
      return this.reply(214, ...reply);
    } else {
      const keys = Object.keys(registryRef);
      const supportedCommands = [];
      for (let i = 0; i < keys.length; i += 5) {
        supportedCommands.push(keys.slice(i, i + 5).join('\t'));
      }
      return this.reply(211, 'Supported commands:', ...supportedCommands, 'Use "HELP [command]" for syntax help.');
    }
  },
  syntax: '{{cmd}} [<command>]',
  description: 'Returns usage documentation on a command if specified, else a general help document is returned',
  flags: {
    no_auth: true
  }
};

export function setHelpRegistry(registry) {
  registryRef = registry;
}

export default help;