"Node. js" Global variables, common tools, file systems

Learning Links: http://www.runoob.com/nodejs/nodejs-global-object.html

In JavaScript, the window is usually a global object, while the global object in node. JS is global, and all global variables (except the global itself) are properties of the global object .

Global objects and global variables

Note: always use var to define variables to avoid introducing global variables, because global variables pollute namespaces and increase the risk of code coupling.

__filename

__dirname

SetTimeout (CB, MS)

Cleartimeout (t)

SetInterval (CB, MS)

Console

Process

Common tools

Util.inherits

Util.inspect

Util.isarray (object)

Util.isregexp (object)

Util.isdate (object)

Util.iserror (object)

File system

The methods in the node. JS File System (FS module) module have asynchronous and synchronous versions, such as functions that read the contents of the file with asynchronous Fs.readfile () and synchronous Fs.readfilesync ().

The last parameter of the Async method function is a callback function, and the first parameter of the callback function contains the error message (ERR).

Open File

The following is the syntax format for opening files in asynchronous mode:

Fs.open (path, flags[, mode], callback)

Get file information

Fs.stat (Path, callback)

Write file

Fs.writefile (file, data[, Options], callback)

Read file

Fs.read (fd, buffer, offset, length, position, callback)

Close File

Fs.close (FD, callback)

Intercepting files

Fs.ftruncate (FD, Len, callback)

deleting files

Fs.unlink (Path, callback)

Create a Directory

Fs.mkdir (path[, mode], callback)

Read Directory

Fs.readdir (Path, callback)

Delete Directory

Fs.rmdir (Path, callback)

"Node. js" Global variables, common tools, file systems