Objective
Although node does a lot of abstract work on the operating system, you can still interact with him directly, such as interacting with processes already in the system, creating a working subprocess. node is a thread for an event loop, but you can create other processes (threads) to work outside of this event loop.
If you are not dealing with command-line tools, there may be few opportunities to use some of the methods or attributes in the process module. But if you're going to do a more complex build tool like Webpack or gulp, because the Bash interface is a tool to communicate directly with the user, the full hint is necessary for a friendly input and output.
Property
A table can probably see what properties the process has
Property name |
Use |
Platform |
Determine 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 |
Point to standard error |
StdErr |
Point to standard error |
We can use this directly in the code.
Console.log (Porcess.platform)
//Darwin
Using argv returns an array of command lines that we can use to get user-specific commands
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 the last of some parameters, the front two do not need, we can
Let args = Process.argv.slice (2);
Console.log (args)
//[' P ', '-V ']
Method
There are a number of methods available for process. There are some of the following that we can use roughly.
cwd
: Returns the path to the working directory where the current script is run
abort
: End Process immediately
nextTick
: Specifies the task to run first in the next event loop
Some of the events supported by the process, through some events, we can do some friendly hints or processing.
uncaughtException
: When the current process throws an unexpected exception that is not caught, it triggers the Uncaughtexception event
message
: Accept messages from the parent process
rejectionHandled
: Used to capture the promise error handling associated with it and the resulting reject
unhandledRejection
: Similarly this is used to capture reject that are not associated with 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 produces a warning when it starts
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
});
Summarize
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