node. JS process module Common Properties and methods

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If you are not dealing with command-line tools, there may be few opportunities for us to use some of the methods or properties in the process module. However, if you want to do a more complex build tool like Webpack or gulp, because the Bash interface is a tool that communicates directly with the user, a friendly input and output, complete hints are all very necessary.

Attribute name Purpose

Platform: Judging the current system platform

ARGV: Array of command-line arguments for the current process

Execpath: The absolute path of the executable file for the current process

STDOUT: point to standard output

STDIN: point to standard input

STDERR: pointing to standard error

STDERR: pointing to standard error

We can use this directly in our code.

Console.log (Porcess.platform)//Darwin

Using argv will return an array of command lines, and we can get the user-specific commands through an array.

Console.log (PROCESS.ARGV); ['/usr/local/bin/node ', '/users/ali-130257n/www/weex-jackzoo/projects/demo.js ', '-p ', '-V ']

In general, we would like to get some final parameters, the first two not required, we can

Let args = Process.argv.slice (2);

Console.log (args)

['-P ', '-V ']

There are many ways that process provides. Roughly what we can use is some of the following.

CWD: Returns the path to the working directory where the current script is running

Abort: End the process immediately

Nexttick: Specifies the task to run first for the next event loop

Some events supported by process, we can do some friendly hints or deal with some events.

Uncaughtexception: The Uncaughtexception event is triggered when the current process throws an unexpected error that is not caught

Message: Accept messages from the parent process

Rejectionhandled: Used to capture the promise error handling associated with it and the resulting reject

Unhandledrejection: The same is the case for capturing reject with no associated promise error handling

Const Unhandledrejections = new Map ();

Process.on (' unhandledrejection ', (reason, p) + = {

Unhandledrejections.set (p, reason);

});

Process.on (' rejectionhandled ', (p) + = {

Unhandledrejections.delete (P);

});

Warning: The current process starts when a warning is generated

Process.on (' Warning ', (warning) + = {

Console.warn (Warning.name); Print The warning name

Console.warn (Warning.message); Print the warning message

Console.warn (Warning.stack); Print the Stack trace

});

node. JS process module Common Properties and methods