Reading files with Node.js
The simplest way to read a file in Node.js is to use the fs.readFile()
method, passing it the file path, encoding and a callback function that will be called with the file data (and the error):
const fs = require('fs')
fs.readFile('/Users/joe/test.txt', 'utf8' , (err, data) => {
if (err) {
console.error(err)
return
}
console.log(data)
})
Alternatively, you can use the synchronous version fs.readFileSync()
:
const fs = require('fs')
try {
const data = fs.readFileSync('/Users/joe/test.txt', 'utf8')
console.log(data)
} catch (err) {
console.error(err)
}
Both fs.readFile()
and fs.readFileSync()
read the full content of the file in memory before returning the data.
This means that big files are going to have a major impact on your memory consumption and speed of execution of the program.
In this case, a better option is to read the file content using streams.