1MB
shell> openssl rand -out hello.txt -base64 $(( 2**20 ))
1GB
shell> openssl rand -out hello.txt -base64 $(( 2**30 ))
const fs = require('fs');
var inp = fs.createReadStream('hello.txt');
var out = fs.createWriteStream('world.txt');
inp.pipe(out);
inp.pipe(process.stdout);
const fs = require('fs');
var zlib = require('zlib');
var inp = fs.createReadStream('file.txt');
var gzip = zlib.createGzip();
var out = fs.createWriteStream('file.txt.gz');
inp.pipe(gzip).pipe(out);
process.stdin.pipe(process.stdout);
const fs = require('fs');
var file = fs.createWriteStream('example.txt');
file.write('hello, ');
file.end('world!');
const fs = require('fs');
var ReadStream = fs.createReadStream('hello.txt', { flags: 'r', autoClose: true, highWaterMark: 1024 * 16 });
var WriteStream = fs.createWriteStream('world.txt', { flags: 'w' });
var myArray = [];
var x = new Boolean(false);
// ReadStream.on('data', (chunk) => {
ReadStream.on('data', function (chunk) {
myArray.push(chunk);
ReadStream.pause();
/*
setTimeout(() => {
ReadStream.resume();
}, 100);
*/
setTimeout(function(){
ReadStream.resume();
}, 100);
});
ReadStream.on('end', function () {
x = true;
console.log('Done.');
});
var timer = setInterval(function () {
if (0 < myArray.length) {
WriteStream.write(myArray.shift());
} else {
if (x) {
clearInterval(timer);
console.log('Done.');
}
}
}, 500);
參考網站：
var Readable = require('stream').Readable;
var rs = new Readable;
rs.push('beep ');
rs.push('boop\n');
rs.push(null);
rs.pipe(process.stdout);
process.stdin.on('data', function (buf) {
console.log(buf);
});
process.stdin.on('end', function () {
console.log('__END__');
});
shell> (echo beep; sleep 1; echo boop) | node app.js
<Buffer 62 65 65 70 0a>
<Buffer 62 6f 6f 70 0a>
__END__
var through = require('through2');
var fs = require('fs');
var stream = through(write, end);
function write(chunk, enc, callback) {
this.push(chunk.toString().toUpperCase());
callback();
}
function end (callback) {
callback();
}
var readable = fs.createReadStream('hello.txt');
readable.pipe(stream).pipe(process.stdout);
// process.stdin.pipe(stream).pipe(process.stdout);
const buf1 = Buffer.alloc(10);
const buf2 = Buffer.alloc(10, 1);
const buf3 = Buffer.allocUnsafe(10);
const buf4 = Buffer.from([1,2,3]);
const buf5 = Buffer.from('test');
const buf6 = Buffer.from('tést', 'utf8');
const buf = Buffer.from('hello world', 'ascii');
console.log(buf.toString('hex'));
console.log(buf.toString('base64'));
const str = '\u00bd + \u00bc = \u00be';
const str = "Node.js";