Object built-in object

Object ChildProcess

child process object

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var child_process = require("child_process"); var child = child_process.spawn("ls");

inheritance relationship

static property

defaultMaxListeners

Integer, the default global maximum number of listeners

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static Integer ChildProcess.defaultMaxListeners;

member attribute

connected

Boolean, query whether the pipeline with the child process is connected normally

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readonly Boolean ChildProcess.connected;

pid

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

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readonly Integer ChildProcess.pid;

exitCode

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

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readonly Integer ChildProcess.exitCode;

stdin

Stream, read the standard input object of the process pointed to by the current object

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readonly Stream ChildProcess.stdin;

stdout

Stream, read the standard output object of the process pointed to by the current object

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readonly Stream ChildProcess.stdout;

stderr

Stream, read the standard error object of the process pointed to by the current object

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readonly Stream ChildProcess.stderr;

onexit

Function, query and bind process exit event, equivalent to on("exit", func);

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Function ChildProcess.onexit;

onmessage

Function, query and bind subprocess message events, equivalent to on("message", func);

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Function ChildProcess.onmessage;

member function

kill

Kill the process pointed to by the current object and send the signal

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ChildProcess.kill(Integer signal);

Call parameters:

  • signal: Integer, the passed signal

Kill the process pointed to by the current object and send the signal

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ChildProcess.kill(String signal);

Call parameters:

  • signal: String, the passed signal

join

Wait for the process pointed to by the current object to end, and return the process end code

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Integer ChildProcess.join() async;

return result:

  • Integer, the end code of the process

disconnect

close ipc pipe with child process

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ChildProcess.disconnect();

send

Send a message to the current child process

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ChildProcess.send(Value msg);

Call parameters:

  • msg: Value, specifies the message to send

usage

Query the memory and time spent by the current process

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Object ChildProcess.usage();

return result:

  • Object, returns a report containing the time

The memory report produces results similar to the following:

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{ "user": 132379, "system": 50507, "rss": 8622080 }

in:

  • user returns the time spent by the process in user code, in microseconds (millionths of a second)
  • system Returns the time the process spent in system code in microseconds (millionths of a second)
  • rss returns the physical memory size currently occupied by the process

on

Bind an event handler to an object

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Object ChildProcess.on(String ev, Function func);

Call parameters:

  • ev: String, the name of the specified event
  • func: Function, specifies the event handler function

return result:

  • Object, returns the event object itself, which is convenient for chain calls

Bind an event handler to an object

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Object ChildProcess.on(Object map);

Call parameters:

  • map: Object, specify the event mapping relationship, the object attribute name will be used as the event name, and the attribute value will be used as the event processing function

return result:

  • Object, returns the event object itself, which is convenient for chain calls

addListener

Bind an event handler to an object

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Object ChildProcess.addListener(String ev, Function func);

Call parameters:

  • ev: String, the name of the specified event
  • func: Function, specifies the event handler function

return result:

  • Object, returns the event object itself, which is convenient for chain calls

Bind an event handler to an object

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Object ChildProcess.addListener(Object map);

Call parameters:

  • map: Object, specify the event mapping relationship, the object attribute name will be used as the event name, and the attribute value will be used as the event processing function

return result:

  • Object, returns the event object itself, which is convenient for chain calls

prependListener

Bind an event handler function to the object start

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Object ChildProcess.prependListener(String ev, Function func);

Call parameters:

  • ev: String, the name of the specified event
  • func: Function, specifies the event handler function

return result:

  • Object, returns the event object itself, which is convenient for chain calls

Bind an event handler function to the object start

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Object ChildProcess.prependListener(Object map);

Call parameters:

  • map: Object, specify the event mapping relationship, the object attribute name will be used as the event name, and the attribute value will be used as the event processing function

return result:

  • Object, returns the event object itself, which is convenient for chain calls

once

Bind a one-time event handler to the object, the one-time handler will only be triggered once

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Object ChildProcess.once(String ev, Function func);

Call parameters:

  • ev: String, the name of the specified event
  • func: Function, specifies the event handler function

return result:

  • Object, returns the event object itself, which is convenient for chain calls

Bind a one-time event handler to the object, the one-time handler will only be triggered once

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Object ChildProcess.once(Object map);

Call parameters:

  • map: Object, specify the event mapping relationship, the object attribute name will be used as the event name, and the attribute value will be used as the event processing function

return result:

  • Object, returns the event object itself, which is convenient for chain calls

prependOnceListener

Bind an event handler function to the object start

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Object ChildProcess.prependOnceListener(String ev, Function func);

Call parameters:

  • ev: String, the name of the specified event
  • func: Function, specifies the event handler function

return result:

  • Object, returns the event object itself, which is convenient for chain calls

Bind an event handler function to the object start

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Object ChildProcess.prependOnceListener(Object map);

Call parameters:

  • map: Object, specify the event mapping relationship, the object attribute name will be used as the event name, and the attribute value will be used as the event processing function

return result:

  • Object, returns the event object itself, which is convenient for chain calls

off

unspecify function from object processing queue

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Object ChildProcess.off(String ev, Function func);

Call parameters:

  • ev: String, the name of the specified event
  • func: Function, specifies the event handler function

return result:

  • Object, returns the event object itself, which is convenient for chain calls

Cancels all functions in the object processing queue

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Object ChildProcess.off(String ev);

Call parameters:

  • ev: String, the name of the specified event

return result:

  • Object, returns the event object itself, which is convenient for chain calls

unspecify function from object processing queue

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Object ChildProcess.off(Object map);

Call parameters:

  • map: Object, specifies the event mapping relationship, the name of the object attribute is used as the event name, and the value of the attribute is used as the event processing function

return result:

  • Object, returns the event object itself, which is convenient for chain calls

removeListener

unspecify function from object processing queue

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Object ChildProcess.removeListener(String ev, Function func);

Call parameters:

  • ev: String, the name of the specified event
  • func: Function, specifies the event handler function

return result:

  • Object, returns the event object itself, which is convenient for chain calls

Cancels all functions in the object processing queue

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Object ChildProcess.removeListener(String ev);

Call parameters:

  • ev: String, the name of the specified event

return result:

  • Object, returns the event object itself, which is convenient for chain calls

unspecify function from object processing queue

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Object ChildProcess.removeListener(Object map);

Call parameters:

  • map: Object, specifies the event mapping relationship, the name of the object attribute is used as the event name, and the value of the attribute is used as the event processing function

return result:

  • Object, returns the event object itself, which is convenient for chain calls

removeAllListeners

Cancels all listeners for all events from the object processing queue, or removes all listeners for the specified event if an event is specified.

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Object ChildProcess.removeAllListeners(String ev);

Call parameters:

  • ev: String, the name of the specified event

return result:

  • Object, returns the event object itself, which is convenient for chain calls

Cancels all listeners for all events from the object processing queue, or removes all listeners for the specified event if an event is specified.

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Object ChildProcess.removeAllListeners(Array evs = []);

Call parameters:

  • evs: Array, the name of the specified event

return result:

  • Object, returns the event object itself, which is convenient for chain calls

setMaxListeners

The default limit on the number of listeners, for compatibility only

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ChildProcess.setMaxListeners(Integer n);

Call parameters:

  • n: Integer, specifies the number of events

getMaxListeners

Gets the default limited number of listeners, for compatibility only

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Integer ChildProcess.getMaxListeners();

return result:

  • Integer, returns the default limit number

listeners

Query the array of listeners for the specified event of the object

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Array ChildProcess.listeners(String ev);

Call parameters:

  • ev: String, the name of the specified event

return result:

  • Array, returns an array of listeners for the specified event

listenerCount

Query the number of listeners for the specified event of the object

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Integer ChildProcess.listenerCount(String ev);

Call parameters:

  • ev: String, the name of the specified event

return result:

  • Integer, returns the number of listeners for the specified event

Query the number of listeners for the specified event of the object

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Integer ChildProcess.listenerCount(Value o, String ev);

Call parameters:

  • o: Value, specifies the object of the query
  • ev: String, the name of the specified event

return result:

  • Integer, returns the number of listeners for the specified event

eventNames

Query listener event name

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Array ChildProcess.eventNames();

return result:

  • Array, returns an array of event names

emit

Actively trigger an event

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Boolean ChildProcess.emit(String ev, ...args);

Call parameters:

  • ev: String, event name
  • args: ..., event parameters, will be passed to the event handler function

return result:

  • Boolean, returns the event trigger status, returns true if there is a response event, otherwise returns false

toString

Return the string representation of the object, generally return "[Native Object]", the object can be reimplemented according to its own characteristics

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String ChildProcess.toString();

return result:

  • String, returns a string representation of the object

toJSON

Returns the JSON format representation of the object, generally returns a collection of readable properties defined by the object

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Value ChildProcess.toJSON(String key = "");

Call parameters:

  • key: String, not used

return result:

  • Value, which returns a JSON-serializable value