Node.js v0.10.47 Manual & Documentation

os#

Stability: 4 - API Frozen

Provides a few basic operating-system related utility functions.

Use require('os') to access this module.

os.tmpdir()#

Returns the operating system's default directory for temp files.

os.endianness()#

Returns the endianness of the CPU. Possible values are "BE" or "LE".

os.hostname()#

Returns the hostname of the operating system.

os.type()#

Returns the operating system name.

os.platform()#

Returns the operating system platform.

os.arch()#

Returns the operating system CPU architecture.

os.release()#

Returns the operating system release.

os.uptime()#

Returns the system uptime in seconds.

os.loadavg()#

Returns an array containing the 1, 5, and 15 minute load averages.

The load average is a measure of system activity, calculated by the operating system and expressed as a fractional number. As a rule of thumb, the load average should ideally be less than the number of logical CPUs in the system.

The load average is a very UNIX-y concept; there is no real equivalent on Windows platforms. That is why this function always returns [0, 0, 0] on Windows.

os.totalmem()#

Returns the total amount of system memory in bytes.

os.freemem()#

Returns the amount of free system memory in bytes.

os.cpus()#

Returns an array of objects containing information about each CPU/core installed: model, speed (in MHz), and times (an object containing the number of milliseconds the CPU/core spent in: user, nice, sys, idle, and irq).

Example inspection of os.cpus: 

[ { model: 'Intel(R) Core(TM) i7 CPU         860  @ 2.80GHz',
    speed: 2926,
    times:
     { user: 252020,
       nice: 0,
       sys: 30340,
       idle: 1070356870,
       irq: 0 } },
  { model: 'Intel(R) Core(TM) i7 CPU         860  @ 2.80GHz',
    speed: 2926,
    times:
     { user: 306960,
       nice: 0,
       sys: 26980,
       idle: 1071569080,
       irq: 0 } },
  { model: 'Intel(R) Core(TM) i7 CPU         860  @ 2.80GHz',
    speed: 2926,
    times:
     { user: 248450,
       nice: 0,
       sys: 21750,
       idle: 1070919370,
       irq: 0 } },
  { model: 'Intel(R) Core(TM) i7 CPU         860  @ 2.80GHz',
    speed: 2926,
    times:
     { user: 256880,
       nice: 0,
       sys: 19430,
       idle: 1070905480,
       irq: 20 } },
  { model: 'Intel(R) Core(TM) i7 CPU         860  @ 2.80GHz',
    speed: 2926,
    times:
     { user: 511580,
       nice: 20,
       sys: 40900,
       idle: 1070842510,
       irq: 0 } },
  { model: 'Intel(R) Core(TM) i7 CPU         860  @ 2.80GHz',
    speed: 2926,
    times:
     { user: 291660,
       nice: 0,
       sys: 34360,
       idle: 1070888000,
       irq: 10 } },
  { model: 'Intel(R) Core(TM) i7 CPU         860  @ 2.80GHz',
    speed: 2926,
    times:
     { user: 308260,
       nice: 0,
       sys: 55410,
       idle: 1071129970,
       irq: 880 } },
  { model: 'Intel(R) Core(TM) i7 CPU         860  @ 2.80GHz',
    speed: 2926,
    times:
     { user: 266450,
       nice: 1480,
       sys: 34920,
       idle: 1072572010,
       irq: 30 } } ]

os.networkInterfaces()#

Get a list of network interfaces: 

{ lo0: 
   [ { address: '::1', family: 'IPv6', internal: true },
     { address: 'fe80::1', family: 'IPv6', internal: true },
     { address: '127.0.0.1', family: 'IPv4', internal: true } ],
  en1: 
   [ { address: 'fe80::cabc:c8ff:feef:f996', family: 'IPv6',
       internal: false },
     { address: '10.0.1.123', family: 'IPv4', internal: false } ],
  vmnet1: [ { address: '10.99.99.254', family: 'IPv4', internal: false } ],
  vmnet8: [ { address: '10.88.88.1', family: 'IPv4', internal: false } ],
  ppp0: [ { address: '10.2.0.231', family: 'IPv4', internal: false } ] }

os.EOL#

A constant defining the appropriate End-of-line marker for the operating system.