Nodejs file and file operations (read/write file deletion and rename)

I learned about node. js most. I learned about the node. js file system today. Here I am looking for some file directory operation instances for node. js file systems. I will share them with you below.

Read/write files
Operations in nodejs are much easier! Let's take a look at several examples.

[Write a text file]
// Wfile. js
------------------------------

The Code is as follows:	Copy code
Var fs = require ("fs "); Var data = 'Hello dashboard '; Fs. writeFile ('C: a.txt ', data, 'ascii', function (err ){ If (err ){ Console. log ('file writing failed '); } Else { Console. log ('Save successfully, hurry and check for garbled id '); } })

------------------------------
[Note: by default, the data encoding is utf8; mode = 438; flag = w]

 

[Read text files]
// Rfile. js
------------------------------

The Code is as follows:	Copy code
Var fs = require ("fs "); Var data = 'Hello dashboard '; Fs. readFile ('C: a.txt ', 'ascii', function (err, data ){ If (err ){ Console. log ('file writing failed '); } Else { Console. log (data ); } })

------------------------------
[NOTE: If no special encoding is available, binary data is returned as a buffer.]
[Note: Binary Buffer data printing result: <Buffer 68 65 6c 6c 6f 20 e8 97 5a a2>]

File directory operations

Nodejs file operations (fs)

When operating files, we need to require (load) the File System package to obtain the File operation function.

The Code is as follows:	Copy code
Var fs = require ("fs ");

How to use this fs? In this case, we need to query the official API of nodejs.

Http://nodejs.org/api/fs.html

Basic file operations include creating, renaming, and deleting. Let's take a look at several examples.

[Create folder]

The Code is as follows:	Copy code
// Newfolder. js ----------------------------- // Load the file system module Var fs = require ("fs "); // Create a folder named a on drive C Fs. mkdir ("c: a", function (err ){ If (! Err ){ Console. log ("operation successful! "); } Else { Console. log ("operation failed! "); } });

-----------------------------
[NOTE: If the folder contains err, an error message is displayed.]

Delete folder]

The Code is as follows:	Copy code
// Removefolder. js ----------------------------- Var fs = require ("fs "); // Delete the folder in drive C Fs. rmdir ("c: a", function (err ){ If (err ){ Console. log ("deletion failed! "); } Else { Console. log ("deleted successfully! "); } });

-----------------------------
[NOTE: If the deleted Folder does not exist, err will have an error message.]

[Rename a folder]
// Rename. js
-----------------------------

The Code is as follows:	Copy code
Var fs = require ("fs "); // Rename the folder to B Fs. rename ("c: a", "C: B", function (err ){ If (err ){ Console. log ("Renaming failed! "); } Else { Console. log ("renamed successfully! "); } });

-----------------------------
[Note: The Folder does not exist, so err will have an error message.]

[Determine whether a file or folder exists]

The Code is as follows:	Copy code
// Exsits. js ----------------------------- Var fs = require ("fs "); // Determine whether the folder exists Fs. exists ("c: a", function (exists ){ If (exists ){ Console. log ("a folder exists "); } Else { Console. log ("folder a does not exist ") } });

-----------------------------
[Note: Then call the callback argument with either true or false
(The value of this callback function is true or false)]

[File type determination] [fs. stat (), fs. lstat () and fs. fstat ()]
// Stat. js
-----------------------------

The Code is as follows:	Copy code
Var fs = require ("fs "); // Obtain the type of the folder Fs. stat ("C: a", function (err, stat ){ If (err ){ Console. log ("the file does not exist! "); } Else { Console. log ("file:" + stat. isFile ()); Console. log ("folder:" + stat. isDirectory ()); } });

-----------------------------
[
Other status functions:

Stats. isFile ()
Stats. isDirectory ()
Stats. isBlockDevice ()
Stats. isCharacterDevice ()
Stats. isSymbolicLink () (only valid for fs. lstat)
Stats. isFIFO ()
Stats. isSocket ()]