如何在節(jié)點(diǎn)中追加文件？我在試著附加日志文件的字符串。但是，寫(xiě)文件在編寫(xiě)字符串之前每次都會(huì)刪除內(nèi)容。fs.writeFile('log.txt', 'Hello Node', function (err) {
if (err) throw err;
console.log('It\'s saved!');}); // => message.txt erased, contains only 'Hello Node'知道怎么用簡(jiǎn)單的方法嗎？
3 回答
拉丁的傳說(shuō)
TA貢獻(xiàn)1789條經(jīng)驗(yàn) 獲得超8個(gè)贊
appendFile
const fs = require('fs');fs.appendFile('message.txt', 'data to append', function (err) {
if (err) throw err;
console.log('Saved!');});const fs = require('fs');fs.appendFileSync('message.txt', 'data to append');
慕婉清6462132
TA貢獻(xiàn)1804條經(jīng)驗(yàn) 獲得超2個(gè)贊
appendFile, appendFileEMFILE
appendFileWriteStream.
appendFile:
console.log(new Date().toISOString());[...Array(10000)].forEach( function (item,index) {
fs.appendFile("append.txt", index+ "\n", function (err) {
if (err) console.log(err);
});});console.log(new Date().toISOString());{ Error: EMFILE: too many open files, open 'C:\mypath\append.txt'
at Error (native)
errno: -4066,
code: 'EMFILE',
syscall: 'open',
path: 'C:\\mypath\\append.txt' }appendFile
var stream = fs.createWriteStream("append.txt", {flags:'a'});console.log(new Date().toISOString());[...Array(10000)].forEach( function (item,index) {
stream.write(index + "\n");});console.log(new Date().toISOString());stream.end();stream.end()AutoClose:true
慕的地8271018
TA貢獻(xiàn)1796條經(jīng)驗(yàn) 獲得超4個(gè)贊
使用createWriteStream的代碼為每次寫(xiě)入創(chuàng)建一個(gè)文件描述符。因?yàn)樗蠊?jié)點(diǎn)在寫(xiě)入后立即關(guān)閉，因此log.end更好。
var fs = require('fs');
var logStream = fs.createWriteStream('log.txt', {'flags': 'a'});
// use {'flags': 'a'} to append and {'flags': 'w'} to erase and write a new file
logStream.write('Initial line...');
logStream.end('this is the end line');
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