Node's Common Built-in Modules
Working with the Operating System
const os = require('os');
os.EOL
os.arch
os.constants
os.cpus
os.endianness
os.freemem
os.getNetworkInterfaces
os.homedir
os.hostname
os.loadavg
os.networkInterfaces
os.platform
os.release
os.tmpDir
os.tmpdir
os.totalmem
os.type
os.uptime
os.userInfo
Working with the File System
const fs = require('fs');
Asynchronous
vs
Synchronous
const fs = require('fs');
// Asynchronous Form:
fs.readFile(__filename, (err, data) => {
if (err) throw err;
// do something with data
});
Asynchronous
const fs = require('fs');
// Synchronous Form:
const data = fs.readFileSync(__filename);
// exceptions are immediately thrown
// do something with data
Synchronous
fs.F_OK
fs.FileReadStream
fs.FileWriteStream
fs.R_OK
fs.ReadStream
fs.Stats
fs.SyncWriteStream
fs.W_OK
fs.WriteStream
fs.X_OK
fs._toUnixTimestamp
fs.access
fs.accessSync
fs.appendFile
fs.appendFileSync
fs.chmod
fs.chmodSync
fs.chown
fs.chownSync
fs.close
fs.closeSync
fs.constants
fs.createReadStream fs.createWriteStream
fs.exists
fs.existsSync
fs.fchmod
fs.fchmodSync
fs.fchown
fs.fchownSync
fs.fdatasync
fs.fdatasyncSync
fs.fstat
fs.fstatSync
fs.fsync
fs.fsyncSync
fs.ftruncate
fs.ftruncateSync
fs.futimes
fs.futimesSync
fs.link
fs.linkSync
fs.lstat
fs.lstatSync
fs.mkdir
fs.mkdirSync
fs.mkdtemp
fs.mkdtempSync
fs.open
fs.openSync
fs.read
fs.readFile
fs.readFileSync
fs.readSync
fs.readdir
fs.readdirSync
fs.readlink
fs.readlinkSync
fs.realpath
fs.realpathSync
fs.rename
fs.renameSync
fs.rmdir
fs.rmdirSync
fs.stat
fs.statSync
fs.symlink
fs.symlinkSync
fs.truncate
fs.truncateSync fs.unlink fs.unlinkSync
fs.unwatchFile fs.utimes fs.utimesSync
fs.watch fs.watchFile fs.write
fs.writeFile fs.writeFileSync fs.writeSync
TASK 1:
Script to fix files in a directory. Each file has its data duplicated. Truncate each file in half.
TASK 2:
Script to clean old files in a directory. Anything older than 7 days should be deleted.
Console and Utilities
console.Console
Util
node
> console.log('One %s', 'thing');
>util.format('One %s', 'thing');
> console.log(module);
> util.inspect(module);
console.assert(3 == '3);
console.trace('here');
Debugging Node.js Applications
node debug index.js
node --inspect --debug-brk index.js
node-inspector
Node's Common Built-in Modules
By Shuhratbek Mamadaliyev
Node's Common Built-in Modules
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