Object ChildProcess
Child process object
1
2var child_process = require("child_process");
var child = child_process.spawn("ls");
Inheritance
Static properties
defaultMaxListeners
Integer, the default global maximum number of listeners
1static Integer ChildProcess.defaultMaxListeners;
Member attributes
pid
Integer, read the id of the process pointed to by the current object
1readonly Integer ChildProcess.pid;
exitCode
Integer, query and set the exit code of the current process
1readonly Integer ChildProcess.exitCode;
stdin
Stream, Read the standard input object of the process pointed to by the current object
1readonly Stream ChildProcess.stdin;
stdout
Stream, Read the standard output object of the process pointed to by the current object
1readonly Stream ChildProcess.stdout;
stderr
Stream, Read the standard error object of the process pointed to by the current object
1readonly Stream ChildProcess.stderr;
onexit
Function, query and bind process exit event, equivalent to on("exit", func);
1Function ChildProcess.onexit;
Member function
kill
Kill the process pointed to by the current object and pass the signal
1ChildProcess.kill(Integer signal);
Call parameters:
- signal: Integer, the signal passed
Kill the process pointed to by the current object and pass the signal
1ChildProcess.kill(String signal);
Call parameters:
- signal: String, the signal passed
join
Wait for the end of the process pointed to by the current object, and return the process end code
1ChildProcess.join() async;
Return result:
- End code of the process
usage
Query the memory and time spent by the current process
1Object ChildProcess.usage();
Return result:
- Object, Return report containing time
The memory report generates results similar to the following:
1
2
3
4
5{
"user": 132379,
"system": 50507,
"rss": 8622080
}
in:
- user returns the time spent by the process in user code, in microseconds (one millionth of a second)
- system returns the time spent by the process in the system code, in microseconds (one millionth of a second)
- rss returns the size of physical memory currently occupied by the process
on
Bind an event handler to the object
1
2Object ChildProcess.on(String ev,
Function func);
Call parameters:
- ev: String, specify the name of the event
- func: Function, specify event processing function
Return result:
- Object, Return the event object itself, which is convenient for chain call
Bind an event handler to the object
1Object ChildProcess.on(Object map);
Call parameters:
- map: Object, specify the event mapping relationship, the object property name will be used as the event name, and the property value will be used as the event processing function
Return result:
- Object, Return the event object itself, which is convenient for chain call
addListener
Bind an event handler to the object
1
2Object ChildProcess.addListener(String ev,
Function func);
Call parameters:
- ev: String, specify the name of the event
- func: Function, specify event processing function
Return result:
- Object, Return the event object itself, which is convenient for chain call
Bind an event handler to the object
1Object ChildProcess.addListener(Object map);
Call parameters:
- map: Object, specify the event mapping relationship, the object property name will be used as the event name, and the property value will be used as the event processing function
Return result:
- Object, Return the event object itself, which is convenient for chain call
prependListener
Bind an event handler to the start of the object
1
2Object ChildProcess.prependListener(String ev,
Function func);
Call parameters:
- ev: String, specify the name of the event
- func: Function, specify event processing function
Return result:
- Object, Return the event object itself, which is convenient for chain call
Bind an event handler to the start of the object
1Object ChildProcess.prependListener(Object map);
Call parameters:
- map: Object, specify the event mapping relationship, the object property name will be used as the event name, and the property value will be used as the event processing function
Return result:
- Object, Return the event object itself, which is convenient for chain call
once
Bind a one-time event processing function to the object, the one-time processing function will only be triggered once
1
2Object ChildProcess.once(String ev,
Function func);
Call parameters:
- ev: String, specify the name of the event
- func: Function, specify event processing function
Return result:
- Object, Return the event object itself, which is convenient for chain call
Bind a one-time event processing function to the object, the one-time processing function will only be triggered once
1Object ChildProcess.once(Object map);
Call parameters:
- map: Object, specify the event mapping relationship, the object property name will be used as the event name, and the property value will be used as the event processing function
Return result:
- Object, Return the event object itself, which is convenient for chain call
prependOnceListener
Bind an event handler to the start of the object
1
2Object ChildProcess.prependOnceListener(String ev,
Function func);
Call parameters:
- ev: String, specify the name of the event
- func: Function, specify event processing function
Return result:
- Object, Return the event object itself, which is convenient for chain call
Bind an event handler to the start of the object
1Object ChildProcess.prependOnceListener(Object map);
Call parameters:
- map: Object, specify the event mapping relationship, the object property name will be used as the event name, and the property value will be used as the event processing function
Return result:
- Object, Return the event object itself, which is convenient for chain call
off
Cancel the specified function from the object processing queue
1
2Object ChildProcess.off(String ev,
Function func);
Call parameters:
- ev: String, specify the name of the event
- func: Function, specify event processing function
Return result:
- Object, Return the event object itself, which is convenient for chain call
Cancel all functions in the object processing queue
1Object ChildProcess.off(String ev);
Call parameters:
- ev: String, specify the name of the event
Return result:
- Object, Return the event object itself, which is convenient for chain call
Cancel the specified function from the object processing queue
1Object ChildProcess.off(Object map);
Call parameters:
- map: Object, specify the event mapping relationship, the object property name is used as the event name, and the property value is used as the event processing function
Return result:
- Object, Return the event object itself, which is convenient for chain call
removeListener
Cancel the specified function from the object processing queue
1
2Object ChildProcess.removeListener(String ev,
Function func);
Call parameters:
- ev: String, specify the name of the event
- func: Function, specify event processing function
Return result:
- Object, Return the event object itself, which is convenient for chain call
Cancel all functions in the object processing queue
1Object ChildProcess.removeListener(String ev);
Call parameters:
- ev: String, specify the name of the event
Return result:
- Object, Return the event object itself, which is convenient for chain call
Cancel the specified function from the object processing queue
1Object ChildProcess.removeListener(Object map);
Call parameters:
- map: Object, specify the event mapping relationship, the object property name is used as the event name, and the property value is used as the event processing function
Return result:
- Object, Return the event object itself, which is convenient for chain call
removeAllListeners
Cancel all the listeners of all events from the object processing queue. If an event is specified, remove all the listeners of the specified event.
1Object ChildProcess.removeAllListeners(String ev);
Call parameters:
- ev: String, specify the name of the event
Return result:
- Object, Return the event object itself, which is convenient for chain call
Cancel all the listeners of all events from the object processing queue. If an event is specified, remove all the listeners of the specified event.
1Object ChildProcess.removeAllListeners(Array evs = []);
Call parameters:
- evs: Array, specify the name of the event
Return result:
- Object, Return the event object itself, which is convenient for chain call
setMaxListeners
The default limit of the number of listeners, only for compatibility
1ChildProcess.setMaxListeners(Integer n);
Call parameters:
- n: Integer, specify the number of events
getMaxListeners
Get the default limit of the number of listeners, only for compatibility
1Integer ChildProcess.getMaxListeners();
Return result:
- Integer, Return to the default limit number
listeners
Array of listeners for the specified event of the query object
1Array ChildProcess.listeners(String ev);
Call parameters:
- ev: String, specify the name of the event
Return result:
- Array, Returns an array of listeners for the specified event
listenerCount
The number of listeners for the specified event of the query object
1Integer ChildProcess.listenerCount(String ev);
Call parameters:
- ev: String, specify the name of the event
Return result:
- Integer, Returns the number of listeners for the specified event
The number of listeners for the specified event of the query object
1
2Integer ChildProcess.listenerCount(Value o,
String ev);
Call parameters:
- o: Value, specify the object of the query
- ev: String, specify the name of the event
Return result:
- Integer, Returns the number of listeners for the specified event
eventNames
Query the event name of the listener
1Array ChildProcess.eventNames();
Return result:
- Array, Returns an array of event names
emit
Trigger an event actively
1
2Boolean ChildProcess.emit(String ev,
...args);
Call parameters:
- ev: String, event name
- args: ..., event parameters, which will be passed to the event handler
Return result:
- Boolean, Return to the event trigger state, return true if there is a response event, otherwise return false
toString
Returns the string representation of the object, generally returns "[Native Object]", the object can be re-implemented according to its own characteristics
1String ChildProcess.toString();
Return result:
- String, Returns the string representation of the object
toJSON
Returns the JSON format representation of the object, generally returns a collection of readable attributes defined by the object
1Value ChildProcess.toJSON(String key = "");
Call parameters:
- key: String, unused
Return result:
- Value, Returns a value containing JSON serializable