kibana-123/src/cli_plugin/lib/logger.js

Kibana is an open source (Apache Licensed), browser based analytics and search dashboard for Elasticsearch. Kibana is a snap to setup and start using. Kibana strives to be easy to get started with, while also being flexible and powerful, just like Elastic

/**
 * Logs messages and errors
 */
export default class Logger {

  constructor(settings) {
    this.previousLineEnded = true;
    this.silent = !!settings.silent;
    this.quiet = !!settings.quiet;
  }

  log(data, sameLine) {
    if (this.silent || this.quiet) return;

    if (!sameLine && !this.previousLineEnded) {
      process.stdout.write('\n');
    }

    //if data is a stream, pipe it.
    if (data.readable) {
      data.pipe(process.stdout);
      return;
    }

    process.stdout.write(data);
    if (!sameLine) process.stdout.write('\n');
    this.previousLineEnded = !sameLine;
  }

  error(data) {
    if (this.silent) return;

    if (!this.previousLineEnded) {
      process.stderr.write('\n');
    }

    //if data is a stream, pipe it.
    if (data.readable) {
      data.pipe(process.stderr);
      return;
    }
    process.stderr.write(`${data}\n`);
    this.previousLineEnded = true;
  };

}