xref: /third_party/node/doc/api/os.json

{
  "type": "module",
  "source": "doc/api/os.md",
  "modules": [
    {
      "textRaw": "OS",
      "name": "os",
      "introduced_in": "v0.10.0",
      "stability": 2,
      "stabilityText": "Stable",
      "desc": "<p><strong>Source Code:</strong> <a href=\"https://github.com/nodejs/node/blob/v18.20.1/lib/os.js\">lib/os.js</a></p>\n<p>The <code>node:os</code> module provides operating system-related utility methods and\nproperties. It can be accessed using:</p>\n<pre><code class=\"language-js\">const os = require('node:os');\n</code></pre>",
      "properties": [
        {
          "textRaw": "`EOL` {string}",
          "type": "string",
          "name": "EOL",
          "meta": {
            "added": [
              "v0.7.8"
            ],
            "changes": []
          },
          "desc": "<p>The operating system-specific end-of-line marker.</p>\n<ul>\n<li><code>\\n</code> on POSIX</li>\n<li><code>\\r\\n</code> on Windows</li>\n</ul>"
        },
        {
          "textRaw": "`constants` {Object}",
          "type": "Object",
          "name": "constants",
          "meta": {
            "added": [
              "v6.3.0"
            ],
            "changes": []
          },
          "desc": "<p>Contains commonly used operating system-specific constants for error codes,\nprocess signals, and so on. The specific constants defined are described in\n<a href=\"#os-constants\">OS constants</a>.</p>"
        },
        {
          "textRaw": "`devNull` {string}",
          "type": "string",
          "name": "devNull",
          "meta": {
            "added": [
              "v16.3.0",
              "v14.18.0"
            ],
            "changes": []
          },
          "desc": "<p>The platform-specific file path of the null device.</p>\n<ul>\n<li><code>\\\\.\\nul</code> on Windows</li>\n<li><code>/dev/null</code> on POSIX</li>\n</ul>"
        }
      ],
      "methods": [
        {
          "textRaw": "`os.availableParallelism()`",
          "type": "method",
          "name": "availableParallelism",
          "meta": {
            "added": [
              "v18.14.0"
            ],
            "changes": []
          },
          "signatures": [
            {
              "return": {
                "textRaw": "Returns: {integer}",
                "name": "return",
                "type": "integer"
              },
              "params": []
            }
          ],
          "desc": "<p>Returns an estimate of the default amount of parallelism a program should use.\nAlways returns a value greater than zero.</p>\n<p>This function is a small wrapper about libuv's <a href=\"https://docs.libuv.org/en/v1.x/misc.html#c.uv_available_parallelism\"><code>uv_available_parallelism()</code></a>.</p>"
        },
        {
          "textRaw": "`os.arch()`",
          "type": "method",
          "name": "arch",
          "meta": {
            "added": [
              "v0.5.0"
            ],
            "changes": []
          },
          "signatures": [
            {
              "return": {
                "textRaw": "Returns: {string}",
                "name": "return",
                "type": "string"
              },
              "params": []
            }
          ],
          "desc": "<p>Returns the operating system CPU architecture for which the Node.js binary was\ncompiled. Possible values are <code>'arm'</code>, <code>'arm64'</code>, <code>'ia32'</code>, <code>'mips'</code>,\n<code>'mipsel'</code>, <code>'ppc'</code>, <code>'ppc64'</code>, <code>'s390'</code>, <code>'s390x'</code>, and <code>'x64'</code>.</p>\n<p>The return value is equivalent to <a href=\"process.html#processarch\"><code>process.arch</code></a>.</p>"
        },
        {
          "textRaw": "`os.cpus()`",
          "type": "method",
          "name": "cpus",
          "meta": {
            "added": [
              "v0.3.3"
            ],
            "changes": []
          },
          "signatures": [
            {
              "return": {
                "textRaw": "Returns: {Object\\[]}",
                "name": "return",
                "type": "Object\\[]"
              },
              "params": []
            }
          ],
          "desc": "<p>Returns an array of objects containing information about each logical CPU core.\nThe array will be empty if no CPU information is available, such as if the\n<code>/proc</code> file system is unavailable.</p>\n<p>The properties included on each object include:</p>\n<ul>\n<li><code>model</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type\" class=\"type\">&lt;string&gt;</a></li>\n<li><code>speed</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type\" class=\"type\">&lt;number&gt;</a> (in MHz)</li>\n<li><code>times</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object\" class=\"type\">&lt;Object&gt;</a>\n<ul>\n<li><code>user</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type\" class=\"type\">&lt;number&gt;</a> The number of milliseconds the CPU has spent in user mode.</li>\n<li><code>nice</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type\" class=\"type\">&lt;number&gt;</a> The number of milliseconds the CPU has spent in nice mode.</li>\n<li><code>sys</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type\" class=\"type\">&lt;number&gt;</a> The number of milliseconds the CPU has spent in sys mode.</li>\n<li><code>idle</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type\" class=\"type\">&lt;number&gt;</a> The number of milliseconds the CPU has spent in idle mode.</li>\n<li><code>irq</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type\" class=\"type\">&lt;number&gt;</a> The number of milliseconds the CPU has spent in irq mode.</li>\n</ul>\n</li>\n</ul>\n<!-- eslint-disable semi -->\n<pre><code class=\"language-js\">[\n  {\n    model: 'Intel(R) Core(TM) i7 CPU         860  @ 2.80GHz',\n    speed: 2926,\n    times: {\n      user: 252020,\n      nice: 0,\n      sys: 30340,\n      idle: 1070356870,\n      irq: 0,\n    },\n  },\n  {\n    model: 'Intel(R) Core(TM) i7 CPU         860  @ 2.80GHz',\n    speed: 2926,\n    times: {\n      user: 306960,\n      nice: 0,\n      sys: 26980,\n      idle: 1071569080,\n      irq: 0,\n    },\n  },\n  {\n    model: 'Intel(R) Core(TM) i7 CPU         860  @ 2.80GHz',\n    speed: 2926,\n    times: {\n      user: 248450,\n      nice: 0,\n      sys: 21750,\n      idle: 1070919370,\n      irq: 0,\n    },\n  },\n  {\n    model: 'Intel(R) Core(TM) i7 CPU         860  @ 2.80GHz',\n    speed: 2926,\n    times: {\n      user: 256880,\n      nice: 0,\n      sys: 19430,\n      idle: 1070905480,\n      irq: 20,\n    },\n  },\n]\n</code></pre>\n<p><code>nice</code> values are POSIX-only. On Windows, the <code>nice</code> values of all processors\nare always 0.</p>\n<p><code>os.cpus().length</code> should not be used to calculate the amount of parallelism\navailable to an application. Use\n<a href=\"#osavailableparallelism\"><code>os.availableParallelism()</code></a> for this purpose.</p>"
        },
        {
          "textRaw": "`os.endianness()`",
          "type": "method",
          "name": "endianness",
          "meta": {
            "added": [
              "v0.9.4"
            ],
            "changes": []
          },
          "signatures": [
            {
              "return": {
                "textRaw": "Returns: {string}",
                "name": "return",
                "type": "string"
              },
              "params": []
            }
          ],
          "desc": "<p>Returns a string identifying the endianness of the CPU for which the Node.js\nbinary was compiled.</p>\n<p>Possible values are <code>'BE'</code> for big endian and <code>'LE'</code> for little endian.</p>"
        },
        {
          "textRaw": "`os.freemem()`",
          "type": "method",
          "name": "freemem",
          "meta": {
            "added": [
              "v0.3.3"
            ],
            "changes": []
          },
          "signatures": [
            {
              "return": {
                "textRaw": "Returns: {integer}",
                "name": "return",
                "type": "integer"
              },
              "params": []
            }
          ],
          "desc": "<p>Returns the amount of free system memory in bytes as an integer.</p>"
        },
        {
          "textRaw": "`os.getPriority([pid])`",
          "type": "method",
          "name": "getPriority",
          "meta": {
            "added": [
              "v10.10.0"
            ],
            "changes": []
          },
          "signatures": [
            {
              "return": {
                "textRaw": "Returns: {integer}",
                "name": "return",
                "type": "integer"
              },
              "params": [
                {
                  "textRaw": "`pid` {integer} The process ID to retrieve scheduling priority for. **Default:** `0`.",
                  "name": "pid",
                  "type": "integer",
                  "default": "`0`",
                  "desc": "The process ID to retrieve scheduling priority for."
                }
              ]
            }
          ],
          "desc": "<p>Returns the scheduling priority for the process specified by <code>pid</code>. If <code>pid</code> is\nnot provided or is <code>0</code>, the priority of the current process is returned.</p>"
        },
        {
          "textRaw": "`os.homedir()`",
          "type": "method",
          "name": "homedir",
          "meta": {
            "added": [
              "v2.3.0"
            ],
            "changes": []
          },
          "signatures": [
            {
              "return": {
                "textRaw": "Returns: {string}",
                "name": "return",
                "type": "string"
              },
              "params": []
            }
          ],
          "desc": "<p>Returns the string path of the current user's home directory.</p>\n<p>On POSIX, it uses the <code>$HOME</code> environment variable if defined. Otherwise it\nuses the <a href=\"https://en.wikipedia.org/wiki/User_identifier#Effective_user_ID\">effective UID</a> to look up the user's home directory.</p>\n<p>On Windows, it uses the <code>USERPROFILE</code> environment variable if defined.\nOtherwise it uses the path to the profile directory of the current user.</p>"
        },
        {
          "textRaw": "`os.hostname()`",
          "type": "method",
          "name": "hostname",
          "meta": {
            "added": [
              "v0.3.3"
            ],
            "changes": []
          },
          "signatures": [
            {
              "return": {
                "textRaw": "Returns: {string}",
                "name": "return",
                "type": "string"
              },
              "params": []
            }
          ],
          "desc": "<p>Returns the host name of the operating system as a string.</p>"
        },
        {
          "textRaw": "`os.loadavg()`",
          "type": "method",
          "name": "loadavg",
          "meta": {
            "added": [
              "v0.3.3"
            ],
            "changes": []
          },
          "signatures": [
            {
              "return": {
                "textRaw": "Returns: {number\\[]}",
                "name": "return",
                "type": "number\\[]"
              },
              "params": []
            }
          ],
          "desc": "<p>Returns an array containing the 1, 5, and 15 minute load averages.</p>\n<p>The load average is a measure of system activity calculated by the operating\nsystem and expressed as a fractional number.</p>\n<p>The load average is a Unix-specific concept. On Windows, the return value is\nalways <code>[0, 0, 0]</code>.</p>"
        },
        {
          "textRaw": "`os.machine()`",
          "type": "method",
          "name": "machine",
          "meta": {
            "added": [
              "v18.9.0"
            ],
            "changes": []
          },
          "signatures": [
            {
              "return": {
                "textRaw": "Returns {string}",
                "name": "return",
                "type": "string"
              },
              "params": []
            }
          ],
          "desc": "<p>Returns the machine type as a string, such as <code>arm</code>, <code>arm64</code>, <code>aarch64</code>,\n<code>mips</code>, <code>mips64</code>, <code>ppc64</code>, <code>ppc64le</code>, <code>s390</code>, <code>s390x</code>, <code>i386</code>, <code>i686</code>, <code>x86_64</code>.</p>\n<p>On POSIX systems, the machine type is determined by calling\n<a href=\"https://linux.die.net/man/3/uname\"><code>uname(3)</code></a>. On Windows, <code>RtlGetVersion()</code> is used, and if it is not\navailable, <code>GetVersionExW()</code> will be used. See\n<a href=\"https://en.wikipedia.org/wiki/Uname#Examples\">https://en.wikipedia.org/wiki/Uname#Examples</a> for more information.</p>"
        },
        {
          "textRaw": "`os.networkInterfaces()`",
          "type": "method",
          "name": "networkInterfaces",
          "meta": {
            "added": [
              "v0.6.0"
            ],
            "changes": [
              {
                "version": "v18.4.0",
                "pr-url": "https://github.com/nodejs/node/pull/43054",
                "description": "The `family` property now returns a string instead of a number."
              },
              {
                "version": "v18.0.0",
                "pr-url": "https://github.com/nodejs/node/pull/41431",
                "description": "The `family` property now returns a number instead of a string."
              }
            ]
          },
          "signatures": [
            {
              "return": {
                "textRaw": "Returns: {Object}",
                "name": "return",
                "type": "Object"
              },
              "params": []
            }
          ],
          "desc": "<p>Returns an object containing network interfaces that have been assigned a\nnetwork address.</p>\n<p>Each key on the returned object identifies a network interface. The associated\nvalue is an array of objects that each describe an assigned network address.</p>\n<p>The properties available on the assigned network address object include:</p>\n<ul>\n<li><code>address</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type\" class=\"type\">&lt;string&gt;</a> The assigned IPv4 or IPv6 address</li>\n<li><code>netmask</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type\" class=\"type\">&lt;string&gt;</a> The IPv4 or IPv6 network mask</li>\n<li><code>family</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type\" class=\"type\">&lt;string&gt;</a> Either <code>IPv4</code> or <code>IPv6</code></li>\n<li><code>mac</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type\" class=\"type\">&lt;string&gt;</a> The MAC address of the network interface</li>\n<li><code>internal</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type\" class=\"type\">&lt;boolean&gt;</a> <code>true</code> if the network interface is a loopback or\nsimilar interface that is not remotely accessible; otherwise <code>false</code></li>\n<li><code>scopeid</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type\" class=\"type\">&lt;number&gt;</a> The numeric IPv6 scope ID (only specified when <code>family</code>\nis <code>IPv6</code>)</li>\n<li><code>cidr</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type\" class=\"type\">&lt;string&gt;</a> The assigned IPv4 or IPv6 address with the routing prefix\nin CIDR notation. If the <code>netmask</code> is invalid, this property is set\nto <code>null</code>.</li>\n</ul>\n<!-- eslint-skip -->\n<pre><code class=\"language-js\">{\n  lo: [\n    {\n      address: '127.0.0.1',\n      netmask: '255.0.0.0',\n      family: 'IPv4',\n      mac: '00:00:00:00:00:00',\n      internal: true,\n      cidr: '127.0.0.1/8'\n    },\n    {\n      address: '::1',\n      netmask: 'ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff',\n      family: 'IPv6',\n      mac: '00:00:00:00:00:00',\n      scopeid: 0,\n      internal: true,\n      cidr: '::1/128'\n    }\n  ],\n  eth0: [\n    {\n      address: '192.168.1.108',\n      netmask: '255.255.255.0',\n      family: 'IPv4',\n      mac: '01:02:03:0a:0b:0c',\n      internal: false,\n      cidr: '192.168.1.108/24'\n    },\n    {\n      address: 'fe80::a00:27ff:fe4e:66a1',\n      netmask: 'ffff:ffff:ffff:ffff::',\n      family: 'IPv6',\n      mac: '01:02:03:0a:0b:0c',\n      scopeid: 1,\n      internal: false,\n      cidr: 'fe80::a00:27ff:fe4e:66a1/64'\n    }\n  ]\n}\n</code></pre>"
        },
        {
          "textRaw": "`os.platform()`",
          "type": "method",
          "name": "platform",
          "meta": {
            "added": [
              "v0.5.0"
            ],
            "changes": []
          },
          "signatures": [
            {
              "return": {
                "textRaw": "Returns: {string}",
                "name": "return",
                "type": "string"
              },
              "params": []
            }
          ],
          "desc": "<p>Returns a string identifying the operating system platform for which\nthe Node.js binary was compiled. The value is set at compile time.\nPossible values are <code>'aix'</code>, <code>'darwin'</code>, <code>'freebsd'</code>,<code>'linux'</code>,\n<code>'openbsd'</code>, <code>'sunos'</code>, and <code>'win32'</code>.</p>\n<p>The return value is equivalent to <a href=\"process.html#processplatform\"><code>process.platform</code></a>.</p>\n<p>The value <code>'android'</code> may also be returned if Node.js is built on the Android\noperating system. <a href=\"https://github.com/nodejs/node/blob/HEAD/BUILDING.md#androidandroid-based-devices-eg-firefox-os\">Android support is experimental</a>.</p>"
        },
        {
          "textRaw": "`os.release()`",
          "type": "method",
          "name": "release",
          "meta": {
            "added": [
              "v0.3.3"
            ],
            "changes": []
          },
          "signatures": [
            {
              "return": {
                "textRaw": "Returns: {string}",
                "name": "return",
                "type": "string"
              },
              "params": []
            }
          ],
          "desc": "<p>Returns the operating system as a string.</p>\n<p>On POSIX systems, the operating system release is determined by calling\n<a href=\"https://linux.die.net/man/3/uname\"><code>uname(3)</code></a>. On Windows, <code>GetVersionExW()</code> is used. See\n<a href=\"https://en.wikipedia.org/wiki/Uname#Examples\">https://en.wikipedia.org/wiki/Uname#Examples</a> for more information.</p>"
        },
        {
          "textRaw": "`os.setPriority([pid, ]priority)`",
          "type": "method",
          "name": "setPriority",
          "meta": {
            "added": [
              "v10.10.0"
            ],
            "changes": []
          },
          "signatures": [
            {
              "params": [
                {
                  "textRaw": "`pid` {integer} The process ID to set scheduling priority for. **Default:** `0`.",
                  "name": "pid",
                  "type": "integer",
                  "default": "`0`",
                  "desc": "The process ID to set scheduling priority for."
                },
                {
                  "textRaw": "`priority` {integer} The scheduling priority to assign to the process.",
                  "name": "priority",
                  "type": "integer",
                  "desc": "The scheduling priority to assign to the process."
                }
              ]
            }
          ],
          "desc": "<p>Attempts to set the scheduling priority for the process specified by <code>pid</code>. If\n<code>pid</code> is not provided or is <code>0</code>, the process ID of the current process is used.</p>\n<p>The <code>priority</code> input must be an integer between <code>-20</code> (high priority) and <code>19</code>\n(low priority). Due to differences between Unix priority levels and Windows\npriority classes, <code>priority</code> is mapped to one of six priority constants in\n<code>os.constants.priority</code>. When retrieving a process priority level, this range\nmapping may cause the return value to be slightly different on Windows. To avoid\nconfusion, set <code>priority</code> to one of the priority constants.</p>\n<p>On Windows, setting priority to <code>PRIORITY_HIGHEST</code> requires elevated user\nprivileges. Otherwise the set priority will be silently reduced to\n<code>PRIORITY_HIGH</code>.</p>"
        },
        {
          "textRaw": "`os.tmpdir()`",
          "type": "method",
          "name": "tmpdir",
          "meta": {
            "added": [
              "v0.9.9"
            ],
            "changes": [
              {
                "version": "v2.0.0",
                "pr-url": "https://github.com/nodejs/node/pull/747",
                "description": "This function is now cross-platform consistent and no longer returns a path with a trailing slash on any platform."
              }
            ]
          },
          "signatures": [
            {
              "return": {
                "textRaw": "Returns: {string}",
                "name": "return",
                "type": "string"
              },
              "params": []
            }
          ],
          "desc": "<p>Returns the operating system's default directory for temporary files as a\nstring.</p>"
        },
        {
          "textRaw": "`os.totalmem()`",
          "type": "method",
          "name": "totalmem",
          "meta": {
            "added": [
              "v0.3.3"
            ],
            "changes": []
          },
          "signatures": [
            {
              "return": {
                "textRaw": "Returns: {integer}",
                "name": "return",
                "type": "integer"
              },
              "params": []
            }
          ],
          "desc": "<p>Returns the total amount of system memory in bytes as an integer.</p>"
        },
        {
          "textRaw": "`os.type()`",
          "type": "method",
          "name": "type",
          "meta": {
            "added": [
              "v0.3.3"
            ],
            "changes": []
          },
          "signatures": [
            {
              "return": {
                "textRaw": "Returns: {string}",
                "name": "return",
                "type": "string"
              },
              "params": []
            }
          ],
          "desc": "<p>Returns the operating system name as returned by <a href=\"https://linux.die.net/man/3/uname\"><code>uname(3)</code></a>. For example, it\nreturns <code>'Linux'</code> on Linux, <code>'Darwin'</code> on macOS, and <code>'Windows_NT'</code> on Windows.</p>\n<p>See <a href=\"https://en.wikipedia.org/wiki/Uname#Examples\">https://en.wikipedia.org/wiki/Uname#Examples</a> for additional information\nabout the output of running <a href=\"https://linux.die.net/man/3/uname\"><code>uname(3)</code></a> on various operating systems.</p>"
        },
        {
          "textRaw": "`os.uptime()`",
          "type": "method",
          "name": "uptime",
          "meta": {
            "added": [
              "v0.3.3"
            ],
            "changes": [
              {
                "version": "v10.0.0",
                "pr-url": "https://github.com/nodejs/node/pull/20129",
                "description": "The result of this function no longer contains a fraction component on Windows."
              }
            ]
          },
          "signatures": [
            {
              "return": {
                "textRaw": "Returns: {integer}",
                "name": "return",
                "type": "integer"
              },
              "params": []
            }
          ],
          "desc": "<p>Returns the system uptime in number of seconds.</p>"
        },
        {
          "textRaw": "`os.userInfo([options])`",
          "type": "method",
          "name": "userInfo",
          "meta": {
            "added": [
              "v6.0.0"
            ],
            "changes": []
          },
          "signatures": [
            {
              "return": {
                "textRaw": "Returns: {Object}",
                "name": "return",
                "type": "Object"
              },
              "params": [
                {
                  "textRaw": "`options` {Object}",
                  "name": "options",
                  "type": "Object",
                  "options": [
                    {
                      "textRaw": "`encoding` {string} Character encoding used to interpret resulting strings. If `encoding` is set to `'buffer'`, the `username`, `shell`, and `homedir` values will be `Buffer` instances. **Default:** `'utf8'`.",
                      "name": "encoding",
                      "type": "string",
                      "default": "`'utf8'`",
                      "desc": "Character encoding used to interpret resulting strings. If `encoding` is set to `'buffer'`, the `username`, `shell`, and `homedir` values will be `Buffer` instances."
                    }
                  ]
                }
              ]
            }
          ],
          "desc": "<p>Returns information about the currently effective user. On POSIX platforms,\nthis is typically a subset of the password file. The returned object includes\nthe <code>username</code>, <code>uid</code>, <code>gid</code>, <code>shell</code>, and <code>homedir</code>. On Windows, the <code>uid</code> and\n<code>gid</code> fields are <code>-1</code>, and <code>shell</code> is <code>null</code>.</p>\n<p>The value of <code>homedir</code> returned by <code>os.userInfo()</code> is provided by the operating\nsystem. This differs from the result of <code>os.homedir()</code>, which queries\nenvironment variables for the home directory before falling back to the\noperating system response.</p>\n<p>Throws a <a href=\"errors.html#class-systemerror\"><code>SystemError</code></a> if a user has no <code>username</code> or <code>homedir</code>.</p>"
        },
        {
          "textRaw": "`os.version()`",
          "type": "method",
          "name": "version",
          "meta": {
            "added": [
              "v13.11.0",
              "v12.17.0"
            ],
            "changes": []
          },
          "signatures": [
            {
              "return": {
                "textRaw": "Returns {string}",
                "name": "return",
                "type": "string"
              },
              "params": []
            }
          ],
          "desc": "<p>Returns a string identifying the kernel version.</p>\n<p>On POSIX systems, the operating system release is determined by calling\n<a href=\"https://linux.die.net/man/3/uname\"><code>uname(3)</code></a>. On Windows, <code>RtlGetVersion()</code> is used, and if it is not\navailable, <code>GetVersionExW()</code> will be used. See\n<a href=\"https://en.wikipedia.org/wiki/Uname#Examples\">https://en.wikipedia.org/wiki/Uname#Examples</a> for more information.</p>"
        }
      ],
      "modules": [
        {
          "textRaw": "OS constants",
          "name": "os_constants",
          "desc": "<p>The following constants are exported by <code>os.constants</code>.</p>\n<p>Not all constants will be available on every operating system.</p>",
          "modules": [
            {
              "textRaw": "Signal constants",
              "name": "signal_constants",
              "meta": {
                "changes": [
                  {
                    "version": "v5.11.0",
                    "pr-url": "https://github.com/nodejs/node/pull/6093",
                    "description": "Added support for `SIGINFO`."
                  }
                ]
              },
              "desc": "<p>The following signal constants are exported by <code>os.constants.signals</code>.</p>\n<table>\n  <tr>\n    <th>Constant</th>\n    <th>Description</th>\n  </tr>\n  <tr>\n    <td><code>SIGHUP</code></td>\n    <td>Sent to indicate when a controlling terminal is closed or a parent\n    process exits.</td>\n  </tr>\n  <tr>\n    <td><code>SIGINT</code></td>\n    <td>Sent to indicate when a user wishes to interrupt a process\n    (<kbd>Ctrl</kbd>+<kbd>C</kbd>).</td>\n  </tr>\n  <tr>\n    <td><code>SIGQUIT</code></td>\n    <td>Sent to indicate when a user wishes to terminate a process and perform a\n    core dump.</td>\n  </tr>\n  <tr>\n    <td><code>SIGILL</code></td>\n    <td>Sent to a process to notify that it has attempted to perform an illegal,\n    malformed, unknown, or privileged instruction.</td>\n  </tr>\n  <tr>\n    <td><code>SIGTRAP</code></td>\n    <td>Sent to a process when an exception has occurred.</td>\n  </tr>\n  <tr>\n    <td><code>SIGABRT</code></td>\n    <td>Sent to a process to request that it abort.</td>\n  </tr>\n  <tr>\n    <td><code>SIGIOT</code></td>\n    <td>Synonym for <code>SIGABRT</code></td>\n  </tr>\n  <tr>\n    <td><code>SIGBUS</code></td>\n    <td>Sent to a process to notify that it has caused a bus error.</td>\n  </tr>\n  <tr>\n    <td><code>SIGFPE</code></td>\n    <td>Sent to a process to notify that it has performed an illegal arithmetic\n    operation.</td>\n  </tr>\n  <tr>\n    <td><code>SIGKILL</code></td>\n    <td>Sent to a process to terminate it immediately.</td>\n  </tr>\n  <tr>\n    <td><code>SIGUSR1</code> <code>SIGUSR2</code></td>\n    <td>Sent to a process to identify user-defined conditions.</td>\n  </tr>\n  <tr>\n    <td><code>SIGSEGV</code></td>\n    <td>Sent to a process to notify of a segmentation fault.</td>\n  </tr>\n  <tr>\n    <td><code>SIGPIPE</code></td>\n    <td>Sent to a process when it has attempted to write to a disconnected\n    pipe.</td>\n  </tr>\n  <tr>\n    <td><code>SIGALRM</code></td>\n    <td>Sent to a process when a system timer elapses.</td>\n  </tr>\n  <tr>\n    <td><code>SIGTERM</code></td>\n    <td>Sent to a process to request termination.</td>\n  </tr>\n  <tr>\n    <td><code>SIGCHLD</code></td>\n    <td>Sent to a process when a child process terminates.</td>\n  </tr>\n  <tr>\n    <td><code>SIGSTKFLT</code></td>\n    <td>Sent to a process to indicate a stack fault on a coprocessor.</td>\n  </tr>\n  <tr>\n    <td><code>SIGCONT</code></td>\n    <td>Sent to instruct the operating system to continue a paused process.</td>\n  </tr>\n  <tr>\n    <td><code>SIGSTOP</code></td>\n    <td>Sent to instruct the operating system to halt a process.</td>\n  </tr>\n  <tr>\n    <td><code>SIGTSTP</code></td>\n    <td>Sent to a process to request it to stop.</td>\n  </tr>\n  <tr>\n    <td><code>SIGBREAK</code></td>\n    <td>Sent to indicate when a user wishes to interrupt a process.</td>\n  </tr>\n  <tr>\n    <td><code>SIGTTIN</code></td>\n    <td>Sent to a process when it reads from the TTY while in the\n    background.</td>\n  </tr>\n  <tr>\n    <td><code>SIGTTOU</code></td>\n    <td>Sent to a process when it writes to the TTY while in the\n    background.</td>\n  </tr>\n  <tr>\n    <td><code>SIGURG</code></td>\n    <td>Sent to a process when a socket has urgent data to read.</td>\n  </tr>\n  <tr>\n    <td><code>SIGXCPU</code></td>\n    <td>Sent to a process when it has exceeded its limit on CPU usage.</td>\n  </tr>\n  <tr>\n    <td><code>SIGXFSZ</code></td>\n    <td>Sent to a process when it grows a file larger than the maximum\n    allowed.</td>\n  </tr>\n  <tr>\n    <td><code>SIGVTALRM</code></td>\n    <td>Sent to a process when a virtual timer has elapsed.</td>\n  </tr>\n  <tr>\n    <td><code>SIGPROF</code></td>\n    <td>Sent to a process when a system timer has elapsed.</td>\n  </tr>\n  <tr>\n    <td><code>SIGWINCH</code></td>\n    <td>Sent to a process when the controlling terminal has changed its\n    size.</td>\n  </tr>\n  <tr>\n    <td><code>SIGIO</code></td>\n    <td>Sent to a process when I/O is available.</td>\n  </tr>\n  <tr>\n    <td><code>SIGPOLL</code></td>\n    <td>Synonym for <code>SIGIO</code></td>\n  </tr>\n  <tr>\n    <td><code>SIGLOST</code></td>\n    <td>Sent to a process when a file lock has been lost.</td>\n  </tr>\n  <tr>\n    <td><code>SIGPWR</code></td>\n    <td>Sent to a process to notify of a power failure.</td>\n  </tr>\n  <tr>\n    <td><code>SIGINFO</code></td>\n    <td>Synonym for <code>SIGPWR</code></td>\n  </tr>\n  <tr>\n    <td><code>SIGSYS</code></td>\n    <td>Sent to a process to notify of a bad argument.</td>\n  </tr>\n  <tr>\n    <td><code>SIGUNUSED</code></td>\n    <td>Synonym for <code>SIGSYS</code></td>\n  </tr>\n</table>",
              "type": "module",
              "displayName": "Signal constants"
            },
            {
              "textRaw": "Error constants",
              "name": "error_constants",
              "desc": "<p>The following error constants are exported by <code>os.constants.errno</code>.</p>",
              "modules": [
                {
                  "textRaw": "POSIX error constants",
                  "name": "posix_error_constants",
                  "desc": "<table>\n  <tr>\n    <th>Constant</th>\n    <th>Description</th>\n  </tr>\n  <tr>\n    <td><code>E2BIG</code></td>\n    <td>Indicates that the list of arguments is longer than expected.</td>\n  </tr>\n  <tr>\n    <td><code>EACCES</code></td>\n    <td>Indicates that the operation did not have sufficient permissions.</td>\n  </tr>\n  <tr>\n    <td><code>EADDRINUSE</code></td>\n    <td>Indicates that the network address is already in use.</td>\n  </tr>\n  <tr>\n    <td><code>EADDRNOTAVAIL</code></td>\n    <td>Indicates that the network address is currently unavailable for\n    use.</td>\n  </tr>\n  <tr>\n    <td><code>EAFNOSUPPORT</code></td>\n    <td>Indicates that the network address family is not supported.</td>\n  </tr>\n  <tr>\n    <td><code>EAGAIN</code></td>\n    <td>Indicates that there is no data available and to try the\n    operation again later.</td>\n  </tr>\n  <tr>\n    <td><code>EALREADY</code></td>\n    <td>Indicates that the socket already has a pending connection in\n    progress.</td>\n  </tr>\n  <tr>\n    <td><code>EBADF</code></td>\n    <td>Indicates that a file descriptor is not valid.</td>\n  </tr>\n  <tr>\n    <td><code>EBADMSG</code></td>\n    <td>Indicates an invalid data message.</td>\n  </tr>\n  <tr>\n    <td><code>EBUSY</code></td>\n    <td>Indicates that a device or resource is busy.</td>\n  </tr>\n  <tr>\n    <td><code>ECANCELED</code></td>\n    <td>Indicates that an operation was canceled.</td>\n  </tr>\n  <tr>\n    <td><code>ECHILD</code></td>\n    <td>Indicates that there are no child processes.</td>\n  </tr>\n  <tr>\n    <td><code>ECONNABORTED</code></td>\n    <td>Indicates that the network connection has been aborted.</td>\n  </tr>\n  <tr>\n    <td><code>ECONNREFUSED</code></td>\n    <td>Indicates that the network connection has been refused.</td>\n  </tr>\n  <tr>\n    <td><code>ECONNRESET</code></td>\n    <td>Indicates that the network connection has been reset.</td>\n  </tr>\n  <tr>\n    <td><code>EDEADLK</code></td>\n    <td>Indicates that a resource deadlock has been avoided.</td>\n  </tr>\n  <tr>\n    <td><code>EDESTADDRREQ</code></td>\n    <td>Indicates that a destination address is required.</td>\n  </tr>\n  <tr>\n    <td><code>EDOM</code></td>\n    <td>Indicates that an argument is out of the domain of the function.</td>\n  </tr>\n  <tr>\n    <td><code>EDQUOT</code></td>\n    <td>Indicates that the disk quota has been exceeded.</td>\n  </tr>\n  <tr>\n    <td><code>EEXIST</code></td>\n    <td>Indicates that the file already exists.</td>\n  </tr>\n  <tr>\n    <td><code>EFAULT</code></td>\n    <td>Indicates an invalid pointer address.</td>\n  </tr>\n  <tr>\n    <td><code>EFBIG</code></td>\n    <td>Indicates that the file is too large.</td>\n  </tr>\n  <tr>\n    <td><code>EHOSTUNREACH</code></td>\n    <td>Indicates that the host is unreachable.</td>\n  </tr>\n  <tr>\n    <td><code>EIDRM</code></td>\n    <td>Indicates that the identifier has been removed.</td>\n  </tr>\n  <tr>\n    <td><code>EILSEQ</code></td>\n    <td>Indicates an illegal byte sequence.</td>\n  </tr>\n  <tr>\n    <td><code>EINPROGRESS</code></td>\n    <td>Indicates that an operation is already in progress.</td>\n  </tr>\n  <tr>\n    <td><code>EINTR</code></td>\n    <td>Indicates that a function call was interrupted.</td>\n  </tr>\n  <tr>\n    <td><code>EINVAL</code></td>\n    <td>Indicates that an invalid argument was provided.</td>\n  </tr>\n  <tr>\n    <td><code>EIO</code></td>\n    <td>Indicates an otherwise unspecified I/O error.</td>\n  </tr>\n  <tr>\n    <td><code>EISCONN</code></td>\n    <td>Indicates that the socket is connected.</td>\n  </tr>\n  <tr>\n    <td><code>EISDIR</code></td>\n    <td>Indicates that the path is a directory.</td>\n  </tr>\n  <tr>\n    <td><code>ELOOP</code></td>\n    <td>Indicates too many levels of symbolic links in a path.</td>\n  </tr>\n  <tr>\n    <td><code>EMFILE</code></td>\n    <td>Indicates that there are too many open files.</td>\n  </tr>\n  <tr>\n    <td><code>EMLINK</code></td>\n    <td>Indicates that there are too many hard links to a file.</td>\n  </tr>\n  <tr>\n    <td><code>EMSGSIZE</code></td>\n    <td>Indicates that the provided message is too long.</td>\n  </tr>\n  <tr>\n    <td><code>EMULTIHOP</code></td>\n    <td>Indicates that a multihop was attempted.</td>\n  </tr>\n  <tr>\n    <td><code>ENAMETOOLONG</code></td>\n    <td>Indicates that the filename is too long.</td>\n  </tr>\n  <tr>\n    <td><code>ENETDOWN</code></td>\n    <td>Indicates that the network is down.</td>\n  </tr>\n  <tr>\n    <td><code>ENETRESET</code></td>\n    <td>Indicates that the connection has been aborted by the network.</td>\n  </tr>\n  <tr>\n    <td><code>ENETUNREACH</code></td>\n    <td>Indicates that the network is unreachable.</td>\n  </tr>\n  <tr>\n    <td><code>ENFILE</code></td>\n    <td>Indicates too many open files in the system.</td>\n  </tr>\n  <tr>\n    <td><code>ENOBUFS</code></td>\n    <td>Indicates that no buffer space is available.</td>\n  </tr>\n  <tr>\n    <td><code>ENODATA</code></td>\n    <td>Indicates that no message is available on the stream head read\n    queue.</td>\n  </tr>\n  <tr>\n    <td><code>ENODEV</code></td>\n    <td>Indicates that there is no such device.</td>\n  </tr>\n  <tr>\n    <td><code>ENOENT</code></td>\n    <td>Indicates that there is no such file or directory.</td>\n  </tr>\n  <tr>\n    <td><code>ENOEXEC</code></td>\n    <td>Indicates an exec format error.</td>\n  </tr>\n  <tr>\n    <td><code>ENOLCK</code></td>\n    <td>Indicates that there are no locks available.</td>\n  </tr>\n  <tr>\n    <td><code>ENOLINK</code></td>\n    <td>Indications that a link has been severed.</td>\n  </tr>\n  <tr>\n    <td><code>ENOMEM</code></td>\n    <td>Indicates that there is not enough space.</td>\n  </tr>\n  <tr>\n    <td><code>ENOMSG</code></td>\n    <td>Indicates that there is no message of the desired type.</td>\n  </tr>\n  <tr>\n    <td><code>ENOPROTOOPT</code></td>\n    <td>Indicates that a given protocol is not available.</td>\n  </tr>\n  <tr>\n    <td><code>ENOSPC</code></td>\n    <td>Indicates that there is no space available on the device.</td>\n  </tr>\n  <tr>\n    <td><code>ENOSR</code></td>\n    <td>Indicates that there are no stream resources available.</td>\n  </tr>\n  <tr>\n    <td><code>ENOSTR</code></td>\n    <td>Indicates that a given resource is not a stream.</td>\n  </tr>\n  <tr>\n    <td><code>ENOSYS</code></td>\n    <td>Indicates that a function has not been implemented.</td>\n  </tr>\n  <tr>\n    <td><code>ENOTCONN</code></td>\n    <td>Indicates that the socket is not connected.</td>\n  </tr>\n  <tr>\n    <td><code>ENOTDIR</code></td>\n    <td>Indicates that the path is not a directory.</td>\n  </tr>\n  <tr>\n    <td><code>ENOTEMPTY</code></td>\n    <td>Indicates that the directory is not empty.</td>\n  </tr>\n  <tr>\n    <td><code>ENOTSOCK</code></td>\n    <td>Indicates that the given item is not a socket.</td>\n  </tr>\n  <tr>\n    <td><code>ENOTSUP</code></td>\n    <td>Indicates that a given operation is not supported.</td>\n  </tr>\n  <tr>\n    <td><code>ENOTTY</code></td>\n    <td>Indicates an inappropriate I/O control operation.</td>\n  </tr>\n  <tr>\n    <td><code>ENXIO</code></td>\n    <td>Indicates no such device or address.</td>\n  </tr>\n  <tr>\n    <td><code>EOPNOTSUPP</code></td>\n    <td>Indicates that an operation is not supported on the socket. Although\n    <code>ENOTSUP</code> and <code>EOPNOTSUPP</code> have the same value\n    on Linux, according to POSIX.1 these error values should be distinct.)</td>\n  </tr>\n  <tr>\n    <td><code>EOVERFLOW</code></td>\n    <td>Indicates that a value is too large to be stored in a given data\n    type.</td>\n  </tr>\n  <tr>\n    <td><code>EPERM</code></td>\n    <td>Indicates that the operation is not permitted.</td>\n  </tr>\n  <tr>\n    <td><code>EPIPE</code></td>\n    <td>Indicates a broken pipe.</td>\n  </tr>\n  <tr>\n    <td><code>EPROTO</code></td>\n    <td>Indicates a protocol error.</td>\n  </tr>\n  <tr>\n    <td><code>EPROTONOSUPPORT</code></td>\n    <td>Indicates that a protocol is not supported.</td>\n  </tr>\n  <tr>\n    <td><code>EPROTOTYPE</code></td>\n    <td>Indicates the wrong type of protocol for a socket.</td>\n  </tr>\n  <tr>\n    <td><code>ERANGE</code></td>\n    <td>Indicates that the results are too large.</td>\n  </tr>\n  <tr>\n    <td><code>EROFS</code></td>\n    <td>Indicates that the file system is read only.</td>\n  </tr>\n  <tr>\n    <td><code>ESPIPE</code></td>\n    <td>Indicates an invalid seek operation.</td>\n  </tr>\n  <tr>\n    <td><code>ESRCH</code></td>\n    <td>Indicates that there is no such process.</td>\n  </tr>\n  <tr>\n    <td><code>ESTALE</code></td>\n    <td>Indicates that the file handle is stale.</td>\n  </tr>\n  <tr>\n    <td><code>ETIME</code></td>\n    <td>Indicates an expired timer.</td>\n  </tr>\n  <tr>\n    <td><code>ETIMEDOUT</code></td>\n    <td>Indicates that the connection timed out.</td>\n  </tr>\n  <tr>\n    <td><code>ETXTBSY</code></td>\n    <td>Indicates that a text file is busy.</td>\n  </tr>\n  <tr>\n    <td><code>EWOULDBLOCK</code></td>\n    <td>Indicates that the operation would block.</td>\n  </tr>\n  <tr>\n    <td><code>EXDEV</code></td>\n    <td>Indicates an improper link.</td>\n  </tr>\n</table>",
                  "type": "module",
                  "displayName": "POSIX error constants"
                },
                {
                  "textRaw": "Windows-specific error constants",
                  "name": "windows-specific_error_constants",
                  "desc": "<p>The following error codes are specific to the Windows operating system.</p>\n<table>\n  <tr>\n    <th>Constant</th>\n    <th>Description</th>\n  </tr>\n  <tr>\n    <td><code>WSAEINTR</code></td>\n    <td>Indicates an interrupted function call.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEBADF</code></td>\n    <td>Indicates an invalid file handle.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEACCES</code></td>\n    <td>Indicates insufficient permissions to complete the operation.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEFAULT</code></td>\n    <td>Indicates an invalid pointer address.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEINVAL</code></td>\n    <td>Indicates that an invalid argument was passed.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEMFILE</code></td>\n    <td>Indicates that there are too many open files.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEWOULDBLOCK</code></td>\n    <td>Indicates that a resource is temporarily unavailable.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEINPROGRESS</code></td>\n    <td>Indicates that an operation is currently in progress.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEALREADY</code></td>\n    <td>Indicates that an operation is already in progress.</td>\n  </tr>\n  <tr>\n    <td><code>WSAENOTSOCK</code></td>\n    <td>Indicates that the resource is not a socket.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEDESTADDRREQ</code></td>\n    <td>Indicates that a destination address is required.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEMSGSIZE</code></td>\n    <td>Indicates that the message size is too long.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEPROTOTYPE</code></td>\n    <td>Indicates the wrong protocol type for the socket.</td>\n  </tr>\n  <tr>\n    <td><code>WSAENOPROTOOPT</code></td>\n    <td>Indicates a bad protocol option.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEPROTONOSUPPORT</code></td>\n    <td>Indicates that the protocol is not supported.</td>\n  </tr>\n  <tr>\n    <td><code>WSAESOCKTNOSUPPORT</code></td>\n    <td>Indicates that the socket type is not supported.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEOPNOTSUPP</code></td>\n    <td>Indicates that the operation is not supported.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEPFNOSUPPORT</code></td>\n    <td>Indicates that the protocol family is not supported.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEAFNOSUPPORT</code></td>\n    <td>Indicates that the address family is not supported.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEADDRINUSE</code></td>\n    <td>Indicates that the network address is already in use.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEADDRNOTAVAIL</code></td>\n    <td>Indicates that the network address is not available.</td>\n  </tr>\n  <tr>\n    <td><code>WSAENETDOWN</code></td>\n    <td>Indicates that the network is down.</td>\n  </tr>\n  <tr>\n    <td><code>WSAENETUNREACH</code></td>\n    <td>Indicates that the network is unreachable.</td>\n  </tr>\n  <tr>\n    <td><code>WSAENETRESET</code></td>\n    <td>Indicates that the network connection has been reset.</td>\n  </tr>\n  <tr>\n    <td><code>WSAECONNABORTED</code></td>\n    <td>Indicates that the connection has been aborted.</td>\n  </tr>\n  <tr>\n    <td><code>WSAECONNRESET</code></td>\n    <td>Indicates that the connection has been reset by the peer.</td>\n  </tr>\n  <tr>\n    <td><code>WSAENOBUFS</code></td>\n    <td>Indicates that there is no buffer space available.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEISCONN</code></td>\n    <td>Indicates that the socket is already connected.</td>\n  </tr>\n  <tr>\n    <td><code>WSAENOTCONN</code></td>\n    <td>Indicates that the socket is not connected.</td>\n  </tr>\n  <tr>\n    <td><code>WSAESHUTDOWN</code></td>\n    <td>Indicates that data cannot be sent after the socket has been\n    shutdown.</td>\n  </tr>\n  <tr>\n    <td><code>WSAETOOMANYREFS</code></td>\n    <td>Indicates that there are too many references.</td>\n  </tr>\n  <tr>\n    <td><code>WSAETIMEDOUT</code></td>\n    <td>Indicates that the connection has timed out.</td>\n  </tr>\n  <tr>\n    <td><code>WSAECONNREFUSED</code></td>\n    <td>Indicates that the connection has been refused.</td>\n  </tr>\n  <tr>\n    <td><code>WSAELOOP</code></td>\n    <td>Indicates that a name cannot be translated.</td>\n  </tr>\n  <tr>\n    <td><code>WSAENAMETOOLONG</code></td>\n    <td>Indicates that a name was too long.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEHOSTDOWN</code></td>\n    <td>Indicates that a network host is down.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEHOSTUNREACH</code></td>\n    <td>Indicates that there is no route to a network host.</td>\n  </tr>\n  <tr>\n    <td><code>WSAENOTEMPTY</code></td>\n    <td>Indicates that the directory is not empty.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEPROCLIM</code></td>\n    <td>Indicates that there are too many processes.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEUSERS</code></td>\n    <td>Indicates that the user quota has been exceeded.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEDQUOT</code></td>\n    <td>Indicates that the disk quota has been exceeded.</td>\n  </tr>\n  <tr>\n    <td><code>WSAESTALE</code></td>\n    <td>Indicates a stale file handle reference.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEREMOTE</code></td>\n    <td>Indicates that the item is remote.</td>\n  </tr>\n  <tr>\n    <td><code>WSASYSNOTREADY</code></td>\n    <td>Indicates that the network subsystem is not ready.</td>\n  </tr>\n  <tr>\n    <td><code>WSAVERNOTSUPPORTED</code></td>\n    <td>Indicates that the <code>winsock.dll</code> version is out of\n    range.</td>\n  </tr>\n  <tr>\n    <td><code>WSANOTINITIALISED</code></td>\n    <td>Indicates that successful WSAStartup has not yet been performed.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEDISCON</code></td>\n    <td>Indicates that a graceful shutdown is in progress.</td>\n  </tr>\n  <tr>\n    <td><code>WSAENOMORE</code></td>\n    <td>Indicates that there are no more results.</td>\n  </tr>\n  <tr>\n    <td><code>WSAECANCELLED</code></td>\n    <td>Indicates that an operation has been canceled.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEINVALIDPROCTABLE</code></td>\n    <td>Indicates that the procedure call table is invalid.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEINVALIDPROVIDER</code></td>\n    <td>Indicates an invalid service provider.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEPROVIDERFAILEDINIT</code></td>\n    <td>Indicates that the service provider failed to initialized.</td>\n  </tr>\n  <tr>\n    <td><code>WSASYSCALLFAILURE</code></td>\n    <td>Indicates a system call failure.</td>\n  </tr>\n  <tr>\n    <td><code>WSASERVICE_NOT_FOUND</code></td>\n    <td>Indicates that a service was not found.</td>\n  </tr>\n  <tr>\n    <td><code>WSATYPE_NOT_FOUND</code></td>\n    <td>Indicates that a class type was not found.</td>\n  </tr>\n  <tr>\n    <td><code>WSA_E_NO_MORE</code></td>\n    <td>Indicates that there are no more results.</td>\n  </tr>\n  <tr>\n    <td><code>WSA_E_CANCELLED</code></td>\n    <td>Indicates that the call was canceled.</td>\n  </tr>\n  <tr>\n    <td><code>WSAEREFUSED</code></td>\n    <td>Indicates that a database query was refused.</td>\n  </tr>\n</table>",
                  "type": "module",
                  "displayName": "Windows-specific error constants"
                }
              ],
              "type": "module",
              "displayName": "Error constants"
            },
            {
              "textRaw": "dlopen constants",
              "name": "dlopen_constants",
              "desc": "<p>If available on the operating system, the following constants\nare exported in <code>os.constants.dlopen</code>. See <a href=\"http://man7.org/linux/man-pages/man3/dlopen.3.html\"><code>dlopen(3)</code></a> for detailed\ninformation.</p>\n<table>\n  <tr>\n    <th>Constant</th>\n    <th>Description</th>\n  </tr>\n  <tr>\n    <td><code>RTLD_LAZY</code></td>\n    <td>Perform lazy binding. Node.js sets this flag by default.</td>\n  </tr>\n  <tr>\n    <td><code>RTLD_NOW</code></td>\n    <td>Resolve all undefined symbols in the library before dlopen(3)\n    returns.</td>\n  </tr>\n  <tr>\n    <td><code>RTLD_GLOBAL</code></td>\n    <td>Symbols defined by the library will be made available for symbol\n    resolution of subsequently loaded libraries.</td>\n  </tr>\n  <tr>\n    <td><code>RTLD_LOCAL</code></td>\n    <td>The converse of <code>RTLD_GLOBAL</code>. This is the default behavior\n    if neither flag is specified.</td>\n  </tr>\n  <tr>\n    <td><code>RTLD_DEEPBIND</code></td>\n    <td>Make a self-contained library use its own symbols in preference to\n    symbols from previously loaded libraries.</td>\n  </tr>\n</table>",
              "type": "module",
              "displayName": "dlopen constants"
            },
            {
              "textRaw": "Priority constants",
              "name": "priority_constants",
              "meta": {
                "added": [
                  "v10.10.0"
                ],
                "changes": []
              },
              "desc": "<p>The following process scheduling constants are exported by\n<code>os.constants.priority</code>.</p>\n<table>\n  <tr>\n    <th>Constant</th>\n    <th>Description</th>\n  </tr>\n  <tr>\n    <td><code>PRIORITY_LOW</code></td>\n    <td>The lowest process scheduling priority. This corresponds to\n    <code>IDLE_PRIORITY_CLASS</code> on Windows, and a nice value of\n    <code>19</code> on all other platforms.</td>\n  </tr>\n  <tr>\n    <td><code>PRIORITY_BELOW_NORMAL</code></td>\n    <td>The process scheduling priority above <code>PRIORITY_LOW</code> and\n    below <code>PRIORITY_NORMAL</code>. This corresponds to\n    <code>BELOW_NORMAL_PRIORITY_CLASS</code> on Windows, and a nice value of\n    <code>10</code> on all other platforms.</td>\n  </tr>\n  <tr>\n    <td><code>PRIORITY_NORMAL</code></td>\n    <td>The default process scheduling priority. This corresponds to\n    <code>NORMAL_PRIORITY_CLASS</code> on Windows, and a nice value of\n    <code>0</code> on all other platforms.</td>\n  </tr>\n  <tr>\n    <td><code>PRIORITY_ABOVE_NORMAL</code></td>\n    <td>The process scheduling priority above <code>PRIORITY_NORMAL</code> and\n    below <code>PRIORITY_HIGH</code>. This corresponds to\n    <code>ABOVE_NORMAL_PRIORITY_CLASS</code> on Windows, and a nice value of\n    <code>-7</code> on all other platforms.</td>\n  </tr>\n  <tr>\n    <td><code>PRIORITY_HIGH</code></td>\n    <td>The process scheduling priority above <code>PRIORITY_ABOVE_NORMAL</code>\n    and below <code>PRIORITY_HIGHEST</code>. This corresponds to\n    <code>HIGH_PRIORITY_CLASS</code> on Windows, and a nice value of\n    <code>-14</code> on all other platforms.</td>\n  </tr>\n  <tr>\n    <td><code>PRIORITY_HIGHEST</code></td>\n    <td>The highest process scheduling priority. This corresponds to\n    <code>REALTIME_PRIORITY_CLASS</code> on Windows, and a nice value of\n    <code>-20</code> on all other platforms.</td>\n  </tr>\n</table>",
              "type": "module",
              "displayName": "Priority constants"
            },
            {
              "textRaw": "libuv constants",
              "name": "libuv_constants",
              "desc": "<table>\n  <tr>\n    <th>Constant</th>\n    <th>Description</th>\n  </tr>\n  <tr>\n    <td><code>UV_UDP_REUSEADDR</code></td>\n    <td></td>\n  </tr>\n</table>",
              "type": "module",
              "displayName": "libuv constants"
            }
          ],
          "type": "module",
          "displayName": "OS constants"
        }
      ],
      "type": "module",
      "displayName": "OS"
    }
  ]
}