code: async function fsinfo(format){
  
      // try to establish a connection to the module
      await getConnection();
  
      const {metadata, files} = await _nodeMcuConnector.fsinfo();
  
      // json output - third party applications
      if (format == 'json') {
          writeOutput(JSON.stringify({
              files: files,
              meta: metadata
          }));
  
      // raw format - suitable for use in bash scripts
      }else if (format == 'raw'){
          // print fileinfo
          files.forEach(function(file){
              writeOutput(file.name);
          });
  
      }else{
          _mculogger.log('Free Disk Space: ' + metadata.remaining + ' KB | Total: ' + metadata.total + ' KB | ' + files.length + ' Files');
  
          // files found ?
          if (files.length==0){
              _mculogger.log('No Files found - have you created the file-system?');
          }else{
              _mculogger.log('Files stored into Flash (SPIFFS)');
  
              // print fileinfo
              files.forEach(function(file){
                  _mculogger.log(' - ' + file.name + ' (' + file.size + ' Bytes)');
              });
          }
      }
  }
docs: show file-system info