Node.js：在没有尾随换行符的情况下打印到控制台？
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Node.js: printing to console without a trailing newline?
提问by Evan Carroll
Is there a method for printing to the console without a trailing newline? The consoleobject documentationdoesn't say anything regarding that:
有没有一种没有尾随换行符的打印到控制台的方法？该console对象的文档并没有说关于任何东西：
console.log()Prints to stdout with newline. This function can take multiple arguments in a
printf()-like way. Example:console.log('count: %d', count);If formating elements are not found in the first string then
util.inspectis used on each argument.
console.log()使用换行符打印到标准输出。这个函数可以以类似
printf()的方式接受多个参数。例子：console.log('count: %d', count);如果在第一个字符串中找不到格式化元素，则
util.inspect在每个参数上使用它。
回答by onteria_
You can use process.stdout.write():
您可以使用process.stdout.write()：
process.stdout.write("hello: ");
See the docs for details.
回答by defvol
Also, if you want to overwrite messages in the same line, for instance in a countdown, you could add '\r' at the end of the string.
此外，如果您想覆盖同一行中的消息，例如在倒计时中，您可以在字符串末尾添加 '\r'。
process.stdout.write("Downloading " + data.length + " bytes\r");
回答by Yan Te
In Windows console (Linux, too), you should replace '\r'with its equivalent code \033[0G:
在 Windows 控制台（Linux 也是如此）中，您应该替换'\r'为它的等效代码\033[0G：
process.stdout.write('ok3[0G');
This uses a VT220 terminal escape sequence to send the cursor to the first column.
这使用 VT220 终端转义序列将光标发送到第一列。
回答by mraxus
As an expansion/enhancement to the brilliant addition made by @rodowi above regarding being able to overwrite a row:
作为对@rodowi 上面关于能够覆盖一行的精彩添加的扩展/增强：
process.stdout.write("Downloading " + data.length + " bytes\r");
Should you not want the terminal cursor to be located at the first character, as I saw in my code, the consider doing the following:
如果您不希望终端光标位于第一个字符处，如我在代码中所见，请考虑执行以下操作：
let dots = ''
process.stdout.write(`Loading `)
let tmrID = setInterval(() => {
dots += '.'
process.stdout.write(`\rLoading ${dots}`)
}, 1000)
setTimeout(() => {
clearInterval(tmrID)
console.log(`\rLoaded in [3500 ms]`)
}, 3500)
By placing the \rin front of the next print statement the cursor is reset just before the replacing string overwrites the previous.
通过将 放在\r下一个打印语句的前面，光标会在替换字符串覆盖前一个之前重置。
回答by douyw
util.printcan be used also. Read: http://nodejs.org/api/util.html#util_util_print
util.print也可以使用。阅读：http: //nodejs.org/api/util.html#util_util_print
util.print([...])# A synchronous output function. Will block the process, cast each argument to a string then output to stdout. Does not place newlines after each argument.
util.print([...])# 一个同步输出函数。将阻塞进程，将每个参数转换为字符串，然后输出到标准输出。不在每个参数后放置换行符。
An example:
一个例子：
// get total length
var len = parseInt(response.headers['content-length'], 10);
var cur = 0;
// handle the response
response.on('data', function(chunk) {
cur += chunk.length;
util.print("Downloading " + (100.0 * cur / len).toFixed(2) + "% " + cur + " bytes\r");
});
回答by Ahmed Masud
There seem to be many answers suggesting:
似乎有很多答案表明：
process.stdout.write
Error logs should be emitted on:
错误日志应在以下位置发出：
process.stderr
Instead use:
而是使用：
console.error
For anyone who is wonder why process.stdout.write('\033[0G');wasn't doing anything it's because stdoutis buffered and you need to wait for drainevent (more info).
对于任何想知道为什么process.stdout.write('\033[0G');不做任何事情的人来说，这是因为stdout已缓冲并且您需要等待drain事件（更多信息）。
If write returns falseit will fire a drainevent.
如果 write 返回false，它将触发一个drain事件。
回答by Tyguy7
None of these solutions work for me, process.stdout.write('ok\033[0G')and just using '\r'just create a new line but don't overwrite on Mac OSX 10.9.2.
这些解决方案都不适合我，process.stdout.write('ok\033[0G')只是'\r'在 Mac OSX 10.9.2 上创建一个新行但不要覆盖。
EDIT:I had to use this to replace the current line:
编辑：我不得不用它来替换当前行：
process.stdout.write('3[0G');
process.stdout.write('newstuff');
