# Node-讀取路徑(Path/fs)

## Path

const path = require('path');

### path.basename(path[, ext])
取得路徑的最後一部分，第二個參數為檔案格式

path.basename('/foo/bar/baz/asdf/quux.html');
// Returns: 'quux.html'

path.basename('/foo/bar/baz/asdf/quux.html', '.html');
// Returns: 'quux'

### path.__dirname(path)
返回路徑的資料夾名稱，路徑必須為string

path.dirname('/foo/bar/baz/asdf/quux');
// Returns: '/foo/bar/baz/asdf'

### path.join([...paths])
將參數內的字串組起來

path.join('/foo', 'bar', 'baz/asdf', 'quux', '..');
// Returns: '/foo/bar/baz/asdf'

path.join('foo', {}, 'bar');
// Throws 'TypeError: Path must be a string. Received {}'

## fs

const fs = require('fs');

### fs.existsSync(path)
同步檢查路徑中是否已存在文件，如果有匯回傳true，沒有則回傳false

### fs.mkdirSync(path[, options])
同步創建目錄，參數一為要建立目錄的位置，參數二為選填，用於確定如何像遞歸地創建目錄等
### fs.readdir(path[, options], callback)
非同步讀取給定路徑的內容，callback需要兩個參數(err, files)

### fs.writeFileSync(file, data[, options])
將資料同步寫入文件，參數一為要寫入的路徑，參數二為要寫入的資料

### fs.readFileSync(path[, options])
以同步的方式讀取文件

### fs.createReadStream(path[, options])
可以打開及讀取內容

let fs = require('fs'), 
  
// Use fs.createReadStream() method 
// to read the file 
reader = fs.createReadStream('input.txt'); 
  
// Read and disply the file data on console 
reader.on('data', function (chunk) { 
    console.log(chunk.toString()); 
});

### fs.createWriteStream(path[, options])
可將資料寫進文件中，參數一為保存文件的路徑

// Include fs module  
let fs = require('fs'),  
  
// Use fs.createWriteStream() method  
// to write the file  
let writer = fs.createWriteStream('test_gfg.txt')  
  
// Read and disply the file data on console  
writer.write('GeeksforGeeks');