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Module process

Process processing module to manage the resources of the current process

Reference method:

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var process = require('process');

Process event

The process module object is EventEmitter For instance, you can respond to process-level events by registering event listeners.

beforeExit event

When fibjs mission has been empty and no additional work is added in, the event beforeExitis triggered

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process.on('beforeExit', exitCode => {});

Under normal circumstances, if no additional work is added to the task queue, the fibjs process will end. But if the beforeExitcallback listener event bindings, start a new task, such as opening a fiber, then fibjs process will continue to run.

process.exitCodeAs the only parameter passed to the value of beforeExitthe callback function event listener. If the process is about to terminate due to explicit reasons, such as calling directlyprocess.exitOr throw an uncaught exception, the beforeExitevent will not be triggered.

exit event

When fibjs exit, the event exitwill be triggered once all the exitevent binding listener execution is completed, the process will be terminated

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process.on('exit', exitCode => {});

exit The callback function of the event listener has only one input parameter. The value of this parameter can be process.exitCode The attribute value, or call process.exitWhen the method passed exitCodevalue.

Signal event

When the fibjs process receives a signal, it will trigger a signal event. The currently supported signals are SIGINT and SIGTERM. Each event name is represented by the uppercase of the signal name (for example, the event'SIGINT' corresponds to the signal SIGINT).

Signal events are different from other process events. Signal events are preempted. When a signal occurs, regardless of the current ioOperation, or JavaScript operation, will trigger the corresponding event as soon as possible. For example, you can use the following code to interrupt the current application and output the running status:

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var coroutine = require('coroutine');

process.on('SIGINT', () => {
    coroutine.fibers.forEach(f => console.error("Fiber %d:\n%s", f.id, f.stack));
    process.exit();
});

The signal names and their meanings are as follows:

  • SIGINT: When the terminal is running, it can be supported by all platforms, and it can usually be triggered by CTRL+C.
  • SIGTERM: This signal is triggered when the process is killed. Not supported under Windows.

Static function

umask

Change the current umask, Windows does not support this method

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static Integer process.umask(Integer mask);

Call parameters:

  • mask: Integer, specify a new mask

Return result:

  • Integer, Return to the previous mask

Change the current umask, Windows does not support this method

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static Integer process.umask(String mask);

Call parameters:

  • mask: String, specify a new mask, string type octal (eg: "0664")

Return result:

  • Integer, Return to the previous mask

Returns the current umask, Windows does not support this method

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static Integer process.umask();

Return result:

  • Integer, Returns the current mask value

hrtime

Returns the high-precision time of the system. This time has nothing to do with the current time and is only used for high-precision timing

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static Array process.hrtime(Array diff = []);

Call parameters:

  • diff: Array, the initial time for comparison

Return result:

  • Array, Returns the timing time, the format is [seconds, nanoseconds]

exit

Exit the current process and return exitCode as the process result

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static process.exit();

Exit the current process and return the result

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static process.exit(Integer code);

Call parameters:

  • code: Integer, return process result

cwd

Returns the current working path of the operating system

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static String process.cwd();

Return result:

  • String, Return the current system path

chdir

Modify the current working path of the operating system

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static process.chdir(String directory);

Call parameters:

  • directory: String, specify the new path to be set

uptime

Query the running time of the running environment, in seconds

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static Number process.uptime();

Return result:

  • Number, Returns the value representing the time

cpuUsage

Query the time spent by the current process in the user and system code, the value of which is a microsecond value (one millionth of a second)

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static Object process.cpuUsage(Object previousValue = {});

Call parameters:

  • previousValue: Object, specify the time of the last query

Return result:

  • Object, Return report containing time

The memory report generates results similar to the following:

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{
    "user": 132379,
    "system": 50507
}

in:

  • user returns the time spent by the process in user code
  • system returns the time the process spends in the system code

memoryUsage

Query the memory usage report of the current process

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static Object process.memoryUsage();

Return result:

  • Object, Return contains memory report

The memory report generates results similar to the following:

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{
    "rss": 8622080,
    "heapTotal": 4083456,
    "heapUsed": 1621800
}

in:

  • rss returns the size of physical memory currently occupied by the process
  • heapTotal returns the v8 engine heap memory size
  • heapUsed returns the size of the heap memory being used by the v8 engine

nextTick

Start a fiber

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static process.nextTick(Function func,
    ...args);

Call parameters:

  • func: Function, specify the function to be executed by the fiber
  • args: ..., variable parameter sequence, this sequence will be passed to the function in the fiber

binding

Get the internal module of the specified name

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static Value process.binding(String name);

Call parameters:

  • name: String, specify the name of the internal module to be queried

Return result:

  • Value, Return the specified internal module

Static properties

argv

Array, returns the command line parameters of the current process

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static readonly Array process.argv;

execArgv

Array, returns the special command line parameters of the current process, these parameters are used by fibjs to set the operating environment

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static readonly Array process.execArgv;

version

String, return fibjs version string

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static readonly String process.version;

versions

Object, return version information of fibjs and components

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static readonly Object process.versions;

execPath

String, query the full path of the currently running execution file

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static readonly String process.execPath;

env

Object, query the environment variables of the current process

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static readonly Object process.env;

arch

String, query the current cpu environment, possible results are'amd64','arm','arm64','ia32'

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static readonly String process.arch;

platform

String, query the current platform name, possible results are'darwin','freebsd','linux', or'win32'

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static readonly String process.platform;

pid

Integer, read the id of the process pointed to by the current object

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static readonly Integer process.pid;

ppid

Integer, read the id of the parent process pointed to by the current object

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static readonly Integer process.ppid;

stdin

Stream, Query the standard input object of the current process, in tty In TTYInputStream, Otherwise Stream

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static readonly Stream process.stdin;

stdout

Stream, Query the standard output object of the current process, in tty In TTYOutputStream, Otherwise Stream

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static readonly Stream process.stdout;

stderr

Stream, Query the standard error output object of the current process, in tty In TTYOutputStream, Otherwise Stream

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static readonly Stream process.stderr;

exitCode

Integer, query and set the exit code of the current process

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static Integer process.exitCode;
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