I/O file reading and writing

File to read

  1. Read fs.readFileSync synchronously

    const fs = require('fs')
// Read synchronously
// Return a Buffer that stores binary information
// 1 Byte=== 8bit(0/1)
const data = fs.readFileSync('./conf.js')
console.log('data', data.toString())
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  2. Read fs.readFile asynchronously

    const fs = require('fs')
// Read asynchronously
fs.readFile('./test.js'.(err, data) = > {
  if (err) throw err
  console.log('data', data.toString())
})
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  3. Async /await read (promisify)

    / / async/await to read
(async() = > {const fs = require('fs')
  // Util is a library that comes with Node
  // Use promisify to wrap fs.readFile in promise style
  const { promisify } = require('util')
  const readFile = promisify(fs.readFile)
  const data = await readFile('./test.js')
  console.log('data3', data.toString());
})()

process.nextTick(async() = > {const fs = require('fs')
  const { promisify } = require('util')
  const readFile = promisify(fs.readFile)
  const data = await readFile('./test.js')
  console.log('data4', data.toString())
})
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  4. File stream steam

    // Copy an image
// This feature will be used later in the custom CLI tool to implement download dependencies
const fs = require('fs')
const rs = fs.createReadStream('./1.jpeg') // Source file stream
const ws = fs.createWriteStream('./1.copy.jpeg')// The target file stream
rs.pipe(ws)// Create a conduit copy
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