Function _exec

src/exec.js:215–254

(command, options, callback)

//@ **command injection**. For more context, consult the [Security
//@ Guidelines](https://github.com/shelljs/shelljs/wiki/Security-guidelines).
function _exec(command, options, callback) {
  options = options || {};

  var pipe = common.readFromPipe();

  // Callback is defined instead of options.
  if (typeof options === 'function') {
    callback = options;
    options = { async: true };
  }

  // Callback is defined with options.
  if (typeof options === 'object' && typeof callback === 'function') {
    options.async = true;
  }

  options = common.extend({
    silent: common.config.silent,
    fatal: common.config.fatal,
    async: false,
  }, options);

  if (!command) {
    try {
      common.error('must specify command');
    } catch (e) {
      if (options.fatal) {
        throw e;
      }

      return;
    }
  }

  if (options.async) {
    return execAsync(command, options, pipe, callback);
  } else {
    return execSync(command, options, pipe);
  }
}
module.exports = _exec;