electron/docs/api/process.md
John Kleinschmidt 671f5c20f7 Add process properties in lieu of command line options.
Resolves #9139
For certain node command line options, those options can be set via the
process object (process.noDeprecation, process.throwDeprecation,
process.traceDeprecation, and process.traceProcessWarnings) so they are
documented here.

Also, sorted properties and methods alphabetically for easier
readability.
2017-06-21 14:58:44 -04:00

4.7 KiB

process

Extensions to process object.

Process: Main, Renderer

Electron's process object is extended from the Node.js process object. It adds the following events, properties, and methods:

Events

Event: 'loaded'

Emitted when Electron has loaded its internal initialization script and is beginning to load the web page or the main script.

It can be used by the preload script to add removed Node global symbols back to the global scope when node integration is turned off:

// preload.js
const _setImmediate = setImmediate
const _clearImmediate = clearImmediate
process.once('loaded', () => {
  global.setImmediate = _setImmediate
  global.clearImmediate = _clearImmediate
})

Properties

process.defaultApp

A Boolean. When app is started by being passed as parameter to the default app, this property is true in the main process, otherwise it is undefined.

process.mas

A Boolean. For Mac App Store build, this property is true, for other builds it is undefined.

process.noAsar

A Boolean that controls ASAR support inside your application. Setting this to true will disable the support for asar archives in Node's built-in modules.

process.noDeprecation

A Boolean that controls whether or not deprecation warnings are printed to stderr.
Setting this to true will silence deprecation warnings. This property is used instead of the --no-deprecation command line flag.

process.resourcesPath

A String representing the path to the resources directory.

process.throwDeprecation

A Boolean that controls whether or not deprecation warnings will be thrown as exceptions. Setting this to true will throw errors for deprecations. This property is used instead of the --throw-deprecation command line flag.

process.traceDeprecation

A Boolean that controls whether or not deprecations printed to stderr include their stack trace. Setting this to true will print stack traces for deprecations. This property is instead of the --trace-deprecation command line flag.

process.traceProcessWarnings

A Boolean that controls whether or not process warnings printed to stderr include their stack trace. Setting this to true will print stack traces for process warnings (including deprecations). This property is instead of the trace-warnings command line flag.

process.type

A String representing the current process's type, can be "browser" (i.e. main process) or "renderer".

process.versions.chrome

A String representing Chrome's version string.

process.versions.electron

A String representing Electron's version string.

process.windowsStore

A Boolean. If the app is running as a Windows Store app (appx), this property is true, for otherwise it is undefined.

Methods

The process object has the following methods:

process.crash()

Causes the main thread of the current process crash.

process.getCPUUsage()

Returns CPUUsage

process.getIOCounters() Windows Linux

Returns IOCounters

process.getProcessMemoryInfo()

Returns Object:

  • workingSetSize Integer - The amount of memory currently pinned to actual physical RAM.
  • peakWorkingSetSize Integer - The maximum amount of memory that has ever been pinned to actual physical RAM.
  • privateBytes Integer - The amount of memory not shared by other processes, such as JS heap or HTML content.
  • sharedBytes Integer - The amount of memory shared between processes, typically memory consumed by the Electron code itself

Returns an object giving memory usage statistics about the current process. Note that all statistics are reported in Kilobytes.

process.getSystemMemoryInfo()

Returns Object:

  • total Integer - The total amount of physical memory in Kilobytes available to the system.
  • free Integer - The total amount of memory not being used by applications or disk cache.
  • swapTotal Integer - The total amount of swap memory in Kilobytes available to the system. Windows Linux
  • swapFree Integer - The free amount of swap memory in Kilobytes available to the system. Windows Linux

Returns an object giving memory usage statistics about the entire system. Note that all statistics are reported in Kilobytes.

process.hang()

Causes the main thread of the current process hang.

process.setFdLimit(maxDescriptors) macOS Linux

  • maxDescriptors Integer

Sets the file descriptor soft limit to maxDescriptors or the OS hard limit, whichever is lower for the current process.