Nodejs file and file actions (read-write files delete rename)

Read and write files
Nodejs in the operation is relatively simple and much! Let's take a look at some examples.

"Write Text File"
Wfile.js
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The code is as follows	Copy Code
var fs = require ("FS"); var data = ' Hello Rainforest blog '; Fs.writefile (' C:a.txt ', data, ' ASCII ', function (err) { if (err) { Console.log (' Write file failed '); }else{ Console.log (' Save success, hurry to see garbled '); } })

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[Note: By default, the data is encoded as utf8;mode=438; Flag=w]

"Read text file"
Rfile.js
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The code is as follows	Copy Code
var fs = require ("FS"); var data = ' Hello Rainforest blog '; Fs.readfile (' c:a.txt ', ' ASCII ', function (err, data) { if (err) { Console.log (' Write file failed '); }else{ Console.log (data); } })

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[Note: If there is no special encoding, then the binary buffered data is returned.] ]
[Note: Binary buffered data printing results: <buffer 6c 6c 6f E8 A2>]

File directory Operations

Nodejs file operation (FS)

When manipulating files, we need to require (load) the file System package to obtain the document operation function.

The code is as follows	Copy Code
var fs = require ("FS");

And this fs how to use it, this time we need to query Nodejs official API

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

Basic file operations include: New, rename, delete, and so on, to see a few examples

"New Folder"

The code is as follows	Copy Code
Newfolder.js ----------------------------- Load File System module var fs = require ("FS"); Create a folder named A on the C disk Fs.mkdir ("C:a", function (Err) { if (!err) { Console.log ("Operation successful!") "); }else{ Console.log (The operation failed!) "); } });

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[Note: If the folder exists err, there will be an error message.] ]

"Delete Folder"

The code is as follows	Copy Code
Removefolder.js ----------------------------- var fs = require ("FS"); Delete Folder A in C disk Fs.rmdir ("C:a", function (Err) { if (err) { Console.log (delete failed!) "); }else{ Console.log ("Delete succeeded!") "); } });

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[Note: If the delete folder does not exist, err will have an error message.] ]

"Rename Folder"
Rename.js
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The code is as follows	Copy Code
var fs = require ("FS"); Rename Folder A to B Fs.rename ("C:a", "c:b", function (Err) { if (err) { Console.log (rename failed!) "); }else{ Console.log ("Rename succeeded!") "); } });

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[Note: The folder does not exist, so err has an error message.] ]

"Determine if a file/folder exists"

The code is as follows	Copy Code
Exsits.js ----------------------------- var fs = require ("FS"); Determine if a folder exists Fs.exists ("C:a", function (exists) { if (exists) { Console.log ("A folder exists"); }else{ Console.log ("folder A does not exist") } });

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[Note: Then call the ' callback argument with either True or false
(This callback function parameter value is TRUE or false)]

"Judge file Type" [Fs.stat (), Fs.lstat () and Fs.fstat ()]
Stat.js
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The code is as follows	Copy Code
var fs = require ("FS"); Get the type of folder a Fs.stat ("C:a", Function (err, stat) { if (err) { Console.log ("file does not exist!") "); }else{ Console.log ("Whether file:" +stat.isfile ()); Console.log ("Whether folder:" +stat.isdirectory ()); } });

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[
Other State functions:

Stats.isfile ()
Stats.isdirectory ()
Stats.isblockdevice ()
Stats.ischaracterdevice ()
Stats.issymboliclink () (only valid for Fs.lstat ())
Stats.isfifo ()
Stats.issocket ()]