strong-service-install/lib/passwd.js

Install a module as an OS service

// Copyright IBM Corp. 2015. All Rights Reserved.
// Node module: strong-service-install
// This file is licensed under the Artistic License 2.0.
// License text available at https://opensource.org/licenses/Artistic-2.0

'use strict';

// The MIT License (MIT)
//
// Copyright (c) Sindre Sorhus <sindresorhus@gmail.com> (sindresorhus.com)
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

var execFile = require('child_process').execFile;
var fs = require('fs');

module.exports = passwd;

function extractDarwin(line) {
  var cols = line.split(':');

  // Darwin passwd(5)
  // 0 name      User's login name.
  // 1 password  User's encrypted password.
  // 2 uid       User's id.
  // 3 gid       User's login group id.
  // 4 class     User's general classification (unused).
  // 5 change    Password change time.
  // 6 expire    Account expiration time.
  // 7 gecos     User's full name.
  // 8 home_dir  User's home directory.
  // 9 shell     User's login shell.

  return {
    username: cols[0],
    password: cols[1],
    uid: Number(cols[2]),
    gid: Number(cols[3]),
    fullname: cols[7],
    homedir: cols[8],
    shell: cols[9]
  };
}

function extractLinux(line) {
  var cols = line.split(':');

  // Linux passwd(5):
  // 0 login name
  // 1 optional encrypted password
  // 2 numerical user ID
  // 3 numerical group ID
  // 4 user name or comment field
  // 5 user home directory
  // 6 optional user command interpreter

  return {
    username: cols[0],
    password: cols[1],
    uid: Number(cols[2]),
    gid: Number(cols[3]),
    fullname: cols[4] && cols[4].split(',')[0],
    homedir: cols[5],
    shell: cols[6]
  };
}

function getUser(str, username) {
  var lines = str.split('\n');
  var i = 0;
  var l = lines.length;
  var extract = process.platform === 'linux' ? extractLinux : extractDarwin;

  while (i < l) {
    var user = extract(lines[i++]);

    if (user.username === username || user.uid === Number(username)) {
      return user;
    }
  }
}

function passwd(username, cb) {
  if (typeof username !== 'string' && typeof username !== 'number') {
    throw new TypeError('Expected a string or number');
  }

  if (process.platform === 'linux') {
    fs.readFile('/etc/passwd', 'utf8', function(err, passwd) {
      if (err) {
        cb(err);
        return;
      }

      cb(null, getUser(passwd, username));
    });
  } else if (process.platform === 'darwin') {
    execFile('/usr/bin/id', ['-P', username], function(err, stdout) {
      if (err) {
        cb(err);
        return;
      }

      cb(null, getUser(stdout, username));
    });
  } else {
    throw new Error('Platform not supported');
  }
}