如何在節(jié)點中追加文件？我在試著附加日志文件的字符串。但是，寫文件在編寫字符串之前每次都會刪除內(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'知道怎么用簡單的方法嗎？
3 回答
qq_笑_17
TA貢獻1818條經(jīng)驗 獲得超7個贊
appendFile
異步:
const fs = require('fs');fs.appendFile('message.txt', 'data to append', function (err) {
if (err) throw err;
console.log('Saved!');});同步:
const fs = require('fs');fs.appendFileSync('message.txt', 'data to append');
aluckdog
TA貢獻1847條經(jīng)驗 獲得超7個贊
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
蠱毒傳說
TA貢獻1895條經(jīng)驗 獲得超3個贊
使用createWriteStream的代碼為每次寫入創(chuàng)建一個文件描述符。因為它要求節(jié)點在寫入后立即關(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');
- 3 回答
- 0 關(guān)注
- 520 瀏覽
添加回答
舉報
0/150
提交
取消